Database Users

Help! Can't update with OTA or manually to 4.2.1

Today i decided to finally update to 4.2.1 and there after 4.2.2, but when i tried to update with OTA, it stopped 1/3 into the updateting process. Then showed a red exclamation thingy. I tried several times, but all with the same result.
Then i tried to update manually to 4.2 with adb sideload, but that did not work. It stopped after displaying "Verifying system" and then it displayed the following:
assert failed: apply_patch_check("EMMC:/dev/block/platform/sdhci-tegra.3/by-name/LNX:5013504:c48f8e86c73fb2c2ba1794f5ec98e27c9e206ed5:5060608:319331fae14fec8a88063751475fce26bae328e0")
Installation aborted
I am sure if have done anything right, but still can't make it work. The device is completely stock. Please help me D:

You didn't mention the starting condition of the tablet, and that is incredibly important information.
Additionally, you didn't really say whether the first upgrade succeeded. Please be specific and detailed.
The OTAs are patching kits - not full replacements - and thus they:
- must each be applied to a SPECIFIC starting condition, and
- can not be "skipped over"; they need to be performed in sequence.
You should be able to avoid OTAs altogether and flash a full factory image (at least up to JOP40D/4.2.1), but only if you are willing to wipe away all your data (factory reset)
So, say what your current version is - use the "J" release version (e.g. JOP40D, etc) , don't say four-point-whatever.

bftb0 said:
You didn't mention the starting condition of the tablet, and that is incredibly important information.
Additionally, you didn't really say whether the first upgrade succeeded. Please be specific and detailed.
The OTAs are patching kits - not full replacements - and thus they:
- must each be applied to a SPECIFIC starting condition, and
- can not be "skipped over"; they need to be performed in sequence.
You should be able to avoid OTAs altogether and flash a full factory image (at least up to JOP40D/4.2.1), but only if you are willing to wipe away all your data (factory reset)
So, say what your current version is - use the "J" release version (e.g. JOP40D, etc) , don't say four-point-whatever.
Click to expand...
Click to collapse
I am running Build JZO54K and tried to update OTA to JOP40D. All of my attempts of updating have failed. Both OTA and manual.
What do you mean by starting condition?

It would help to know if you have a wi-fi only model or 3g. They take different update files. You have to have the update specific to your model (wi-fi v. 3g). The amount of memory doesn't matter.

Groid said:
It would help to know if you have a wi-fi only model or 3g. They take different update files. You have to have the update specific to your model (wi-fi v. 3g). The amount of memory doesn't matter.
Click to expand...
Click to collapse
It is a 32gb wifi

henrikpw said:
I am running Build JZO54K and tried to update OTA to JOP40D.
Click to expand...
Click to collapse
Thanks, much better info.
henrikpw said:
What do you mean by starting condition?
Click to expand...
Click to collapse
Exactly what you stated above - thanks. In your OP, it wasn't clear whether it was the first OTA or the second OTA that was failing.
The assert fail message you provided revolves around the boot image (LNX partition). It implies a modified boot partition ... but I believe you when you say unmodified stock. (A different user reported a similar case a few days ago, but with a different stock ROM installed... and therefore a different OTA file)
Is it correct to assume this failure occurs when attempting to apply the JZO54K -> JOP40D OTA update?
Let me poke around a little bit, I will respond back. You may have to do a full factory flash - in the meantime have a look at the Carbon app video on Koush's (ClockworkMod) site to see if you are comfortable with doing that process.

bftb0 said:
Is it correct to assume this failure occurs when attempting to apply the JZO54K -> JOP40D OTA update?.
Click to expand...
Click to collapse
Yes.
bftb0 said:
Let me poke around a little bit, I will respond back. You may have to do a full factory flash - in the meantime have a look at the Carbon app video on Koush's (ClockworkMod) site to see if you are comfortable with doing that process.
Click to expand...
Click to collapse
I do not want to do anything that voids my warrenty

henrikpw said:
I do not want to do anything that voids my warrenty
Click to expand...
Click to collapse
Well, if you consider unlocking your bootloader, installing stock software, and then re-locking your bootloader to be a warranty-voiding situation, then there is really only one path available to you: back up all your market apps & data using Carbon, install the (full) factory software**, perform the 4.2.2 OTA, and then restore apps & data with Carbon.
**actually, I'm not completely sure if the factory (full-install) software bundle requires bootloader unlocking or not - I suspect that it might require an unlocked bootloader.
If you have never been through any of this before, I can see that it appears intimidating, esp. because of the number of newbs showing up every day asking "did I just brick my device?"
But using custom recoveries - even temporarily - provides some flexibility even when you want to run pure stock.
For instance, in your case, I believe that boot image check is the very last thing which is checked in your OTA prior to starting. That suggests that removing that check - AND the corresponding boot image patching - would allow everything else in the OTA patch to succeed; after that the complete boot.img file from the JOP40D distro could be manually flashed; and from there you would no doubt be able to proceed to an additional OTA install to get to 4.2.2
But because a modified/re-zipped OTA bundle could not be flashed by the stock recovery due to lack of signing, this flashing would have to be performed by a custom recovery (that has signature checking supressed).
Lastly, I will say this - I doubt that Google made a mistake with their assert() checks in their OTA update package. That suggests that either
- your boot image actually did get mysteriously modified somehow, or
- your device developed a media flaw in it's boot partition, so the checksum validation fails because of this problem.
In the latter instance, that portends a small risk involving future flashing or booting from that partition.
Well, this post has gotten long; maybe you should say something about what risks you *are* willing to take...

Here are some people who have the same problem: http://code.google.com/p/android/issues/detail?id=41819

henrikpw said:
Here are some people who have the same problem: http://code.google.com/p/android/issues/detail?id=41819
Click to expand...
Click to collapse
That's a lot of reports.
The thing that strikes me about this is that the check which fails (boot partition) is the very last item checked before the patching begins. In the case of folks trying the patch manually, it is hard to believe they simply picked the wrong OTA file (corresponding to the wrong release version) - because in that case a whole bunch of files would be mismatched: they would get a very early error in the list of things checked.
It's almost as if a bunch of units escaped Asus with a variation in the boot image.
There might be something more subtle going on too - here's someone on xda who reported the very same syndrome, but was trying to update a completely different OTA - the starting point was JRO03S
Well, as I said, the problem can be overcome manually. But you would probably need to unlock the bootloader, even if you planned on staying with a full stock setup.

Problem getting 4.2.2 update: "Verification failed"

Hey everyone,
I'm having trouble getting my Nexus 7 to update to 4.2.2. My device is rooted, I recently performed a factory reset.
The update has never appeared in my "System updates" menu, so I looked around and saw that if you force stop "Google Services Framework" and clear its data, the update will appear in "System updates."
It did, but when it finishes downloading, it says "Verification failed."
I tried another factory reset, and I had to again force stop and clear data on "Google Services Framework" to get the update to appear, but again it downloads and say "Verification failed."
I'm stumped now. Do I have to unroot and reroot? Do I have to keep waiting for this update? Do anything with the bootloader? (I really hope not...)
Thanks everyone!

If some files in your system got changed for whatever reason, then you wont be able to update. You can flash the 4.2.1 stock rom and try ota update again.

Leonhan said:
If some files in your system got changed for whatever reason, then you wont be able to update. You can flash the 4.2.1 stock rom and try ota update again.
Click to expand...
Click to collapse
Is flashing the stock 4.2.1 rom the same thing as doing a factory reset to 4.2.1?
If it isn't, would flashing the 4.2.1 rom wipe my tablet?

Leonhan said:
If some files in your system got changed for whatever reason, then you wont be able to update. You can flash the 4.2.1 stock rom and try ota update again.
Click to expand...
Click to collapse
If he is trying to do an OTA to 4.2.2, would it not be more straightforward to just flash the 4.2.2 factory image? The OP has already done a factory reset, so it doesn't look like he/she is particularly attached to his current setup.
Also - the language he used was vague - it sort of sounded like the OP observed "verification failed" in the main OS rather than in the recovery. Not sure.
But it doesn't matter - newbs should not be trying to use OTAs on modified /system images or tabs with altered boot images. It's just too detailed a process to describe compactly.
@Horadrius
Before you do anything further, you should back up everything on the "SD Card" to your PC. Yes, all of it. You can throw it away later if you find you didn't need it. But if you follow the instructions for the Google (factory) images install, everything gets wiped off of /data including your pseudo - SD card.
At a minimum, that will allow you to follow the SBS instructions for installing the 4.2.2 factory images, or - you can simply install a 4.2.2 Stock ROM from over in the dev forum.
Whatever you do, start getting in the habit of making backups - and at least occasionally also getting copies of those off of the tablet.

Oh boy, lot of information to digest here....and a lot of questions
it sort of sounded like the OP observed "verification failed" in the main OS rather than in the recovery. Not sure.
Click to expand...
Click to collapse
Yes, it was the main OS - Settings -> About Tablet -> System Update.
After force stopping Google Services Framework, the update showed up there, and when the download bar reached 100%, it said "verification failed." I did a factory reset, and now when I go to System Update it simply says that my system is up to date.
This makes me think I'm not "supposed" to have the update yet, and that it will arrive, eventually. Yes?
newbs should not be trying to use OTAs on modified /system images or tabs with altered boot images.
Click to expand...
Click to collapse
So, no updating the device from System Menu because I'm rooted/unlocked bootloader? I'll have to flash everything as it comes out?
@Horadrius
Before you do anything further, you should back up everything on the "SD Card" to your PC.
Click to expand...
Click to collapse
Would Titanium Backup held in this regard? Or simply copy/paste the sdcard folder to my PC?
This whole process has been very frustrating. Is this the price you pay for rooting your device? Making simple system updates into a maze?

Horadrius said:
Oh boy, lot of information to digest here....and a lot of questions
Yes, it was the main OS - Settings -> About Tablet -> System Update.
After force stopping Google Services Framework, the update showed up there, and when the download bar reached 100%, it said "verification failed." I did a factory reset, and now when I go to System Update it simply says that my system is up to date.
This makes me think I'm not "supposed" to have the update yet, and that it will arrive, eventually. Yes?
So, no updating the device from System Menu because I'm rooted/unlocked bootloader? I'll have to flash everything as it comes out?
Would Titanium Backup held in this regard? Or simply copy/paste the sdcard folder to my PC?
This whole process has been very frustrating. Is this the price you pay for rooting your device? Making simple system updates into a maze?
Click to expand...
Click to collapse
Sounds like your download is bad if it fails at this stage. I believe it is saying the checksum of the download file doesn't match whatever is downloaded.
PS. not related to N7, why XDA use the re-captcha which I need to refresh several times to get something I can read

Horadrius said:
Yes, it was the main OS - Settings -> About Tablet -> System Update.
After force stopping Google Services Framework, the update showed up there, and when the download bar reached 100%, it said "verification failed." I did a factory reset, and now when I go to System Update it simply says that my system is up to date.
This makes me think I'm not "supposed" to have the update yet, and that it will arrive, eventually. Yes?
Click to expand...
Click to collapse
No. It means that for some strange reason, running a checksum program on the downloaded OTA file failed to produce the expected checksum. The most likely way this can happen is that the file is truncated - the download stopped short of the full file. Don't know why this is happening, but there you go. There could be other failure causes that are more rare, but it doesn't mean you are not "supposed" to have the OTA. It means that the download process is failing.
The *stock* recovery does a number of even more sophisticated checking than this; but it appears from your description that the recovery never even gets booted.
Horadrius said:
So, no updating the device from System Menu because I'm rooted/unlocked bootloader?
Click to expand...
Click to collapse
Yes and No. An unlocked bootloader causes no problems at all. ANY of the following CAN or WILL cause problems:
- attempting to run an OTA with a custom recovery installed instead of the stock recovery.
- having a modified boot partition (e.g. non-stock kernel, or slightly modified boot partition)
- having altered (or removed!) files in the /system partition that are targeted for patching.
- permissions changes performed by the installer script can cause root functionality to disappear
Horadrius said:
I'll have to flash everything as it comes out?
Click to expand...
Click to collapse
Not sure what you are asking here, but the basic answer is that if you stay on stock you can certainly apply OTAs easily. If you start altering things, you might or might not be able to apply an OTA; there are simply no guarantees.
[size=+1]OTAs are meant for stock installations - including a stock recovery. PERIOD. While it is possible that an OTA could succeed, it is unreasonable to have the expectation that it will do so.[/size]
Horadrius said:
Would Titanium Backup held in this regard? Or simply copy/paste the sdcard folder to my PC?
Click to expand...
Click to collapse
I presume you are talking about the future here, as you said that you already did a factory reset at least twice. If you have subsequently added stuff back in, then I suppose you might be talking about the present tense.
But, yes - either TiBu or the Carbon app can be used along with a strategy where you simply back up the apps & data you are interested in, (plus any "flashable zips" that you used to customize your device in the first place), and you simply start from scratch with a factory install followed by re-rooting, and then restore your apps & data (using TiBu or Carbon).
One other thing you can do which is EASY is this: simply wait until a developer/ROM cook publishes a "Stock" flashable ROM based on the release that the OTA is upgrading to. Don't worry about the OTA, just wait a little bit. (These ROMs are already out for the WiFi-only model, BTW).
1) Take a backup as the first thing you do. It's easy and gives you some insurance.
2) Don't wipe (no "factory reset") - just install the Stock ROM over the top of your existing ROM.
that's it. If you were using a custom kernel, re-install it.
Horadrius said:
This whole process has been very frustrating. Is this the price you pay for rooting your device? Making simple system updates into a maze?
Click to expand...
Click to collapse
[size=+1]OTAs are meant for stock installations - including a stock recovery. PERIOD.[/size]
Interpret that as you desire. It is unreasonable for you to expect that you can diddle with your phone any way you please, and a patch install upgrade methodology will be robust in the faces of arbitrary changes on your part. You are the person creating the maze, not Google.
Moreover, it is your choice to take an upgrade - it's not mandatory. My guess is your tablet was quite pleasing to you before any OTAs started rolling out. Nobody is forcing you to do anything.
OK, one last thing. It is still possible that a manual OTA can succeed on your phone if it is lightly rooted - but there are no guarantees. The procedure does not require you to wait around until an OTA arrives on your phone, but it is not for the faint-hearted:
1) Download the appropriate Stock OTA File.
2) Re-install the stock recovery onto your tablet. You will have to dig it out of the Google full factory image for the version of the OS you are currently running. (available here)
Code:
fastboot flash recovery factory-4.2.1-recovery.img
3) Soft-boot into a custom recovery, e.g.
Code:
fastboot boot openrecovery-twrp-2.4.1.0-grouper.img
5) Using the command line and adb to communicate with the soft-booted recovery, create a recovery command file:
Code:
C:\myPCsux> adb push 6ece895ecb23.signed-nakasi-JDQ39-from-JOP40D.6ece895e.zip /cache/update.zip
C:\myPCsux> adb shell
# cd /cache/recovery
# cat > command
--update_package=/cache/update.zip
^D # ( that is a Control-D character )
# sync
# reboot recovery
This will either succeed or fail. Based on your comments though, you might just want to overflash a Stock-derived ROM over the top of your existing ROM (a "no-wipe" install).
[ROM][Factory Image][4.2.2] Nakasi -::- Odex, Deodex, Rooted -::- teshxx (02/14/13) <-- NOTE for WiFi (nakasi/grouper) ONLY
good luck with your tab.
Someone once said "Rooting is a lifestyle". There's some truth to that; it eats up your time. Perhaps it is not for you.

Thanks, bftb0.
Looking through your list of reasons for why my OTA might not work, none of them applied to me.
I didn't install any custom recovery (didn't install Clockwork Mod recovery specifically to avoid dealing with flashing roms) or kernels or modify any partitions, nor to my knowledge changed any files in the /system section.
I think I'm going to give this update a week or so to pop up on my update menu before I start tinkering again.
Don't get me wrong - I enjoy this kind of tinkering, and all the perks of rooting, but my knowledge is extremely limited, which is what makes it frustrating trying to find information. The only thing I've done before this is install Cyanogen on my HP Touchpad.
Anyway, do I need to install CWM recovery to flash (overflash?) that 4.2.2 rom you linked?

if you haven't done anything other than rooting(i.e. copying a file su to it), OTA would go through. Your problem is about the download process. It can go wrong for many reasons from the download is bad to what saved to the temp area(where the download is) is bad(rare but still possible).

chimpanzeexda said:
if you haven't done anything other than rooting(i.e. copying a file su to it), OTA would go through. Your problem is about the download process. It can go wrong for many reasons from the download is bad to what saved to the temp area(where the download is) is bad(rare but still possible).
Click to expand...
Click to collapse
That's all I've done, root and unlock bootloader. The download only showed up when I cleared data and force stopped the "Google Services Framework" process. I reboot the system, and check for the update and nothing is there.

well, sounds like you have to flash it manually using fastboot then.
That said, I myself have no intention of doing the update any time soon as I don't find any specific problem with 4.2.1 and there isn't any specific feature i want in 4.2.2

Horadrius said:
Anyway, do I need to install CWM recovery to flash (overflash?) that 4.2.2 rom you linked?
Click to expand...
Click to collapse
TL;DR Yes and No.
People that use toolkits seem to use hard-flashed installs of custom recoveries, as they don't really understand what goes on under the hood, even if the toolkit offers them a means to soft-boot any image the toolkit operator downloads. (I assume that the toolkits probably allow this; as I don't use them I don't know for sure.)
What I am saying is that the answer depends on your knowledge. So long as you have an unlocked bootloader, you can soft-boot any boot image you like - including custom recoveries.. (This also pre-supposes correctly-functioning device drivers, but that is a Windows/user training issue, it has nothing to do with Android).
When I say soft-boot, I mean that the image is transferred to the tablet, which then hands over control and starts executing that image - but it is not "flashed" to Flash memory, so the next time a boot occurs, the same boot images are still stored in either "boot" or "recovery".
In this configuration, the phone should be much more likely to complete an OTA as it will have the stock recovery present most of the time, and only temporarily present when you attach to your PC and kick things off with a custom recovery.
The OTA could still fail, but it probably would succeed for a very lightly rooted stock configuration (other than problems with losing root).
The only downside to this arrangement is that you can't be flashing roms or making nandroid backups or other forms of rooter activities when you are away from the PC.
For the IT-OCD or obsessive ROM hopper, that could be a good thing.
good luck... the rest is up to you.

Ok, I installed Clockwork Mod from a toolkit because going into fastboot and choosing "Recovery mode" led me to a picture of the Android guy with a red triangle on his back saying "No Command."
I'm just going to install 4.2.2 myself now. Question regarding that link - odex/deodexed - I looked up the difference but can't tell which one is appropriate for me - I'm guessing it's odex because that seems to be closer to stock.
Edit: It worked! Thanks for your assistance, everyone!

IMO, google should not ship odex image now that we have fast enough hardware. odex is just a form of 'pre-compilation' which only benefit first time load(or when the cache is cleared). Too little gain for such a complicated setup.

[Q] Trying to upgrade to 4.4+ Kit Kat on N7 with ClockworkMod Recovery installed

Hi everyone,
I'm using QBKing77's tutorial to manually upgrade my Nexus 7 to Kit Kat 4.4 (and up) but haven't been able to with ClockworkMod Recovery installed.
The video I'm using is on YouTube, titled: "Manually Update the Nexus 7 to Android 4.4 KitKat" and at the step at 3:38 I don't know what to do.
(sorry I'm unable to post links bc I'm a new user:crying
CWM doesn't have the 'Apply update from ADB' option that stock Recovery has (or at least I'm not sure what to do in its place).
If anyone knows how I can continue the upgrade process it would really help!
Thanks in advance :good:

hennimore said:
Hi everyone,
I'm using QBKing77's tutorial to manually upgrade my Nexus 7 to Kit Kat 4.4 (and up) but haven't been able to with ClockworkMod Recovery installed.
The video I'm using is on YouTube, titled: "Manually Update the Nexus 7 to Android 4.4 KitKat" and at the step at 3:38 I don't know what to do.
(sorry I'm unable to post links bc I'm a new user:crying
CWM doesn't have the 'Apply update from ADB' option that stock Recovery has (or at least I'm not sure what to do in its place).
If anyone knows how I can continue the upgrade process it would really help!
Thanks in advance :good:
Click to expand...
Click to collapse
Hi, hennimore...
From your post, I assume you have already CWM installed... if so, then upgrading is pretty straightforward. Assuming further, that you can boot your Nexus 7 into Android normally, you can flash an OTA .zip directly from the Nexus 7 itself... without recourse to ADB or a PC.
The first thing to do is to determine the build number of the currently installed version of Android you're running. This is found in SETTINGS>>ABOUT TABLET>>... and at the bottom, will be the build number.
Next, go here where you will find an archive of all currently known OTA .zips for the Nexus 7 (2012)... listed by build number.
Using Chrome (or whatever Android browser you're currently using) download to your Nexus 7, the correct OTA .zip(s) appropriate to your situation. Depending on how old your current version of Android is, you may have to download more than one.
For example... if you're currently running Jellybean 4.2.2, build JDQ39 on a WiFi only 'nakasi/grouper' Nexus 7, the 'update path' is as follows... and the OTA .zips you'll need are...
----------------------------------------------------
JWR66Y from JDQ39
Updates Jellybean 4.2.2 TO Jellybean 4.3
KOT49H from JWR66Y
Updates Jellybean 4.3 TO KitKat 4.4.2
----------------------------------------------------
Keeping in mind this is just an example (your situation maybe different), these should be flashed IN THE ORDER GIVEN ABOVE... slowly bringing your Nexus 7 up to date. From Jellybean 4.2.2 through Jellybean 4.3 and finally arriving at the latest build of Android, KOT49H - KitKat 4.4.2.
It's important you download the OTA's relevant to the type of Nexus 7 you have... so for a WiFi only model, you need 'nakasi/grouper' OTA's... if it's a WiFi/3G model, then you need 'nakasig/tilapia' OTA's.
Now to flash...
Once you've downloaded the OTA zip (or zips) to your Nexus 7... shut down the device completely. Reboot it into the bootloader, with the VOL DOWN+hold, POWER ON key press sequence. Once in the bootloader, and using the VOL BUTTONS, navigate to the RECOVERY MODE option, and press the POWER BUTTON to select. Your device should now boot into CWM.
Once there, select the INSTALL ZIP option, followed by the CHOOSE ZIP FROM /SDCARD option. Navigate (via the 0/ folder) to the /download folder on the internal storage of the Nexus 7... where you should find the OTA .zip(s) you previously downloaded via Chrome or other Android browser. Select NO, YES or GO BACK accordingly.
I'm not sure it matters, but if you have to flash more than one OTA .zip to bring your Nexus 7 up to date, then I recommend booting normally in between flashes... just to make sure everything is working OK.
Unless you're running a really old version of Android, say Jellybean 4.1.2, I can't see it taking more than a couple of reboots into CWM. And if you're currently on Jellybean 4.3, then it's just one OTA .zip flash.
A few caveats...
If you've modified system files in any way, these OTA's will fail, as they expect to find unmodified versions of stock Android system files. If they've been changed, say as a result of a Custom ROM or Custom Kernel flash... then they can't be 'patched', ie., updated... and the OTA will abort, with no changes made.
Root and having a Custom Recovery (CWM or TWRP) installed however, won't block an OTA... although you will loose both during the OTA update procedure.
If you're familiar with fastboot, then it's relatively straightforward to re-acquire them after the OTA update(s).
Hope this helps... and good luck.
Rgrds,
Ged.

Wow really appreciate and very useful for me Mr blake. Thanks a lot. One question, im in stock 4.4 krts160 with root and unlock bootloader with twrp cwm, i m going to flash the newest ota, will this step erase my root and relock my bootloader? Or i watch in youtube post by rootjunkies that twrp can handle ota. What would you suggest the better way. And thanks again for the information.
Sent from my MB855 using xda premium

deny_kei said:
Wow really appreciate and very useful for me Mr blake. Thanks a lot. One question, im in stock 4.4 krts160 with root and unlock bootloader with twrp cwm, i m going to flash the newest ota, will this step erase my root and relock my bootloader? Or i watch in youtube post by rootjunkies that twrp can handle ota. What would you suggest the better way. And thanks again for the information.
Sent from my MB855 using xda premium
Click to expand...
Click to collapse
Hi, deny_kei...
You will loose root, and your Custom Recovery... whether that be TWRP or CWM.
I'm afraid it's unavoidable - it's always been that way with OTA's. You have to fastboot flash your Custom Recovery of choice again afterwards, and re-root... not difficult, but a bit of a nuisance nontheless.
Flashing an OTA, though, will NOT re-lock the bootloader.
The bootloader will remain unlocked until you purposefully choose to relock it with fastboot oem lock.
TWRP should be able to handle an OTA flash. I'm currently using CWM (with which I flashed the KitKat 4.4.2 OTA), but I've never had any problems myself applying OTA's with TWRP in the past.
Rgrds,
Ged.

GedBlake said:
Hi, hennimore...
From your post, I assume you have already CWM installed... if so, then upgrading is pretty straightforward. Assuming further, that you can boot your Nexus 7 into Android normally, you can flash an OTA .zip directly from the Nexus 7 itself... without recourse to ADB or a PC.
The first thing to do is to determine the build number of the currently installed version of Android you're running. This is found in SETTINGS>>ABOUT TABLET>>... and at the bottom, will be the build number.
Next, go here where you will find an archive of all currently known OTA .zips for the Nexus 7 (2012)... listed by build number.
Using Chrome (or whatever Android browser you're currently using) download to your Nexus 7, the correct OTA .zip(s) appropriate to your situation. Depending on how old your current version of Android is, you may have to download more than one.
For example... if you're currently running Jellybean 4.2.2, build JDQ39 on a WiFi only 'nakasi/grouper' Nexus 7, the 'update path' is as follows... and the OTA .zips you'll need are...
----------------------------------------------------
JWR66Y from JDQ39
Updates Jellybean 4.2.2 TO Jellybean 4.3
KOT49H from JWR66Y
Updates Jellybean 4.3 TO KitKat 4.4.2
----------------------------------------------------
Keeping in mind this is just an example (your situation maybe different), these should be flashed IN THE ORDER GIVEN ABOVE... slowly bringing your Nexus 7 up to date. From Jellybean 4.2.2 through Jellybean 4.3 and finally arriving at the latest build of Android, KOT49H - KitKat 4.4.2.
It's important you download the OTA's relevant to the type of Nexus 7 you have... so for a WiFi only model, you need 'nakasi/grouper' OTA's... if it's a WiFi/3G model, then you need 'nakasig/tilapia' OTA's.
Now to flash...
Once you've downloaded the OTA zip (or zips) to your Nexus 7... shut down the device completely. Reboot it into the bootloader, with the VOL DOWN+hold, POWER ON key press sequence. Once in the bootloader, and using the VOL BUTTONS, navigate to the RECOVERY MODE option, and press the POWER BUTTON to select. Your device should now boot into CWM.
Once there, select the INSTALL ZIP option, followed by the CHOOSE ZIP FROM /SDCARD option. Navigate (via the 0/ folder) to the /download folder on the internal storage of the Nexus 7... where you should find the OTA .zip(s) you previously downloaded via Chrome or other Android browser. Select NO, YES or GO BACK accordingly.
I'm not sure it matters, but if you have to flash more than one OTA .zip to bring your Nexus 7 up to date, then I recommend booting normally in between flashes... just to make sure everything is working OK.
Unless you're running a really old version of Android, say Jellybean 4.1.2, I can't see it taking more than a couple of reboots into CWM. And if you're currently on Jellybean 4.3, then it's just one OTA .zip flash.
A few caveats...
If you've modified system files in any way, these OTA's will fail, as they expect to find unmodified versions of stock Android system files. If they've been changed, say as a result of a Custom ROM or Custom Kernel flash... then they can't be 'patched', ie., updated... and the OTA will abort, with no changes made.
Root and having a Custom Recovery (CWM or TWRP) installed however, won't block an OTA... although you will loose both during the OTA update procedure.
If you're familiar with fastboot, then it's relatively straightforward to re-acquire them after the OTA update(s).
Hope this helps... and good luck.
Rgrds,
Ged.
Click to expand...
Click to collapse
Thanks so much for the helpful response! I should have also mentioned that I currently have AOKP running on my N7
(Version: aokp_grouper_jb_build-2 Build number: aokp_grouper-userdebug 4.1.1 JRO03L eng.roman.20120916.095343 test-keys)
I'm not sure how this affects the update process, but would definitely appreciate any other help you can offer.
Thanks again!

hennimore said:
Thanks so much for the helpful response! I should have also mentioned that I currently have AOKP running on my N7
(Version: aokp_grouper_jb_build-2 Build number: aokp_grouper-userdebug 4.1.1 JRO03L eng.roman.20120916.095343 test-keys)
I'm not sure how this affects the update process, but would definitely appreciate any other help you can offer.
Thanks again!
Click to expand...
Click to collapse
Hi, hennimore...
As you're running a Custom ROM, you can pretty much forget about OTA's... as they are only designed to upgrade official stock firmware from Google. If you were to attempt to flash any OTA on your Nexus 7 as it currently stands, it would abort almost immediately during the verification phase of the OTA update process. Because nothing in /system would match what the OTA expects to subsequently 'patch' (update) in the second half of the OTA update process.
Your only option, if you wish to have official stock KitKat installed on your Nexus 7, is to fastboot flash back to factory stock.
For this, you will need the full factory stock image for your Nexus 7, available here.
(Currently, build KOT49H KitKat 4.4.2 is not yet available as a full factory image... just KRT16S KitKat 4.4... but that's not a problem...'cos once you have KitKat 4.4 installed, you can then use an OTA to bring it completely up to date... as detailed in my previous post).
Instructions on how to restore factory stock are available here.
This process is more time consuming than it is technically difficult... because fastboot flashing back to factory stock essentially wipes the device... so before you can begin, you need to backup all of your apps and associated app data with Titanium (requires root), and then backup the entire contents of the Nexus 7's internal storage to your PC... for later restore AFTER you've fastboot flashed KitKat.
Fastboot flashing back to factory stock resets the device, as though it where new. You'll need to set up your WiFi password again... and re-enter your Google Account (gmail) details... and restore all your data from your PC... fastboot flash CWM or TWRP in order to re-root. Once rooted, you can then use Titanium to restore all your apps.
Longwinded and tediously time consuming, it certainly is... but it's the only way to get official KitKat on your Nexus 7 if you're currently running a Custom ROM.
Rgrds,
Ged.

GedBlake said:
Hi, hennimore...
As you're running a Custom ROM, you can pretty much forget about OTA's... as they are only designed to upgrade official stock firmware from Google. If you were to attempt to flash any OTA on your Nexus 7 as it currently stands, it would abort almost immediately during the verification phase of the OTA update process. Because nothing in /system would match what the OTA expects to subsequently 'patch' (update) in the second half of the OTA update process.
Your only option, if you wish to have official stock KitKat installed on your Nexus 7, is to fastboot flash back to factory stock.
For this, you will need the full factory stock image for your Nexus 7, available here.
(Currently, build KOT49H KitKat 4.4.2 is not yet available as a full factory image... just KRT16S KitKat 4.4... but that's not a problem...'cos once you have KitKat 4.4 installed, you can then use an OTA to bring it completely up to date... as detailed in my previous post).
Instructions on how to restore factory stock are available here.
This process is more time consuming than it is technically difficult... because fastboot flashing back to factory stock essentially wipes the device... so before you can begin, you need to backup all of your apps and associated app data with Titanium (requires root), and then backup the entire contents of the Nexus 7's internal storage to your PC... for later restore AFTER you've fastboot flashed KitKat.
Fastboot flashing back to factory stock resets the device, as though it where new. You'll need to set up your WiFi password again... and re-enter your Google Account (gmail) details... and restore all your data from your PC... fastboot flash CWM or TWRP in order to re-root. Once rooted, you can then use Titanium to restore all your apps.
Longwinded and tediously time consuming, it certainly is... but it's the only way to get official KitKat on your Nexus 7 if you're currently running a Custom ROM.
Rgrds,
Ged.
Click to expand...
Click to collapse
Ah, I'm sad to hear that I must flash back, but I appreciate the information! Thanks again for all of you help, hopefully I can complete the process without any hiccups!

Thanks Mr Blake i will considered using ota, nevertheless my last ota i got stuck in the softbrick although my nexus is stock,unlock an unroot.
Thanks for this useful information
Sent from my MB855 using xda premium

I've been following your steps and seem to have hit a wall when I need to install the adb drivers. I went to the link included in your instructions and followed their tutorial for a Windows 7 PC. After coming back to your instructions, I continued to the step with the Command Prompt.
I entered the command correctly as written, however I get no results under the List of devices attached.
I'm not sure if this is related to the problem, but when I am in Device Manager trying to Locate Android Phone in the right pane, all that shows for me is 'Nexus 7' - which I would assume should work.
However, after Right-clicking on 'Nexus 7' (Android Composite ADB Interface doesn't appear) and selecting Update Driver, I continue through the steps to where I must manually update the driver, and I received a message stating, "The best driver software for your device is already installed"
Under that it says, "Windows has determined the driver software for your device is up to date. MTP USB Device"
I'm not sure if you can make anything of this, but I figured I'd ask since you've been so helpful thus far :angel:

Hi guys,
I've been having problems to update to 4.4 in the Nexus 7 wifi version, the only thing I done is unlock the bootloader and root, once I tried the OTA upgrade it starts the process and then it shows up the Android little guy with an error, and doesn't shows the error of installation. I tried once the flashing the zip file using TWRP and it just failed. After the first failed the tablet just started to lag horribly. Any suggestions on how to fix this?
Sent from my Nexus 7 using xda app-developers app

GedBlake said:
Hi, hennimore...
As you're running a Custom ROM, you can pretty much forget about OTA's... as they are only designed to upgrade official stock firmware from Google. If you were to attempt to flash any OTA on your Nexus 7 as it currently stands, it would abort almost immediately during the verification phase of the OTA update process. Because nothing in /system would match what the OTA expects to subsequently 'patch' (update) in the second half of the OTA update process.
Your only option, if you wish to have official stock KitKat installed on your Nexus 7, is to fastboot flash back to factory stock.
For this, you will need the full factory stock image for your Nexus 7, available here.
(Currently, build KOT49H KitKat 4.4.2 is not yet available as a full factory image... just KRT16S KitKat 4.4... but that's not a problem...'cos once you have KitKat 4.4 installed, you can then use an OTA to bring it completely up to date... as detailed in my previous post).
Instructions on how to restore factory stock are available here.
This process is more time consuming than it is technically difficult... because fastboot flashing back to factory stock essentially wipes the device... so before you can begin, you need to backup all of your apps and associated app data with Titanium (requires root), and then backup the entire contents of the Nexus 7's internal storage to your PC... for later restore AFTER you've fastboot flashed KitKat.
Fastboot flashing back to factory stock resets the device, as though it where new. You'll need to set up your WiFi password again... and re-enter your Google Account (gmail) details... and restore all your data from your PC... fastboot flash CWM or TWRP in order to re-root. Once rooted, you can then use Titanium to restore all your apps.
Longwinded and tediously time consuming, it certainly is... but it's the only way to get official KitKat on your Nexus 7 if you're currently running a Custom ROM.
Rgrds,
Ged.
Click to expand...
Click to collapse
Does anyone have any ideas? Thanks!

Hey again, so I was able to get beyond the point where I originally was at a standstill, and now have 4.4 installed on my N7 (Build KRT16S)
So now my question is, do I need to re-root my device, then upgrade to 4.4.2? Or am I currently rooted?
I don't see the option for USB debugging in my settings any longer...
Thanks!!!

I have tried updated ota on my nexus 7 root without unlocking bootloader on 4.3 update and it works fine but you will lost root . Is your nexus root ,unlock bootloader with twrp and stock rom? If thats the case try to update via ota. Ive just manage upgrade to 4.4.2 with ota 10 minutes ago with above situation. I only lost my root not the unlock bootloader. The twrp cwm can handled ota. Thats my advise .
Lets hear advise from others because i also noob in nexus 7
Thanks
Sent from my Nexus 7 using xda premium

hennimore said:
Hey again, so I was able to get beyond the point where I originally was at a standstill, and now have 4.4 installed on my N7 (Build KRT16S)
So now my question is, do I need to re-root my device, then upgrade to 4.4.2? Or am I currently rooted?
I don't see the option for USB debugging in my settings any longer...
Thanks!!!
Click to expand...
Click to collapse
Hi, hennimore...
Sorry it's taken me a while to respond... been busy with family issues (I don't seem to have the time these days that I used to, to focus on Android stuff).
Anyway... taking your questions in order...
hennimore said:
So now my question is, do I need to re-root my device, then upgrade to 4.4.2? Or am I currently rooted?
Click to expand...
Click to collapse
If you've just flashed a clean install of KRT16S, then you certainly won't be rooted. Nor will you have a Custom Recovery installed. You'll be runing 100% totally unmodified stock Android KitKat. The only difference between your Nexus 7 and the average Joe Bloggs' Nexus 7 (who just bought his yesterday)... is your bootloader will be unlocked.
With regard to applying the new update... KOT49H
Well, there are three routes you could go down...
1). Await for the OTA to appear normally in the notification bar, or go to SETTINGS>>ABOUT TABLET > > SYSTEM UPDATES... and tap on the 'check now' button. When the update appears (and sooner or later it will), it will be flashed automatically via stock recovery. This of course, is the standard method by which 99.9% of all Android users get their updates.
2). If you don't fancy waiting, fastboot flash a Custom Recovery, like TWRP or CWM, and then download the KOT49H OTA .zip directly to your Nexus 7. Boot into your Custom Recovery of choice (via the bootloader), and flash it manually.
3). If you haven't done much with your Nexus 7 (ie, installed lots of apps and copied lots of stuff over), since you flashed the full factory image of KRT16S, and you don't mind repeating the process... then the full factory image for KOT49H has now been uploaded by Google, and is available here. Download and flash it the way you did KRT16S. It goes without saying, that this will reset and wipe your device again.
*****
Addendum: It seems that Google have made a bit a mess (of some) of the KitKat 4.4.2 factory stock image download links... and when clicked upon, will give a 404 error message.
The corrected download links can be found here...
http://forum.xda-developers.com/showthread.php?t=2565531
*****
Whichever of these methods you use to upgrade to KOT49H from KRT16S... you'll need to fastboot flash a Custom Recovery afterwards if you wish to re-root.
With regard to USB debugging...
hennimore said:
I don't see the option for USB debugging in my settings any longer...
Click to expand...
Click to collapse
You won't... this is because Developer Options are hidden by default... presumably to prevent non-technically minded people from screwing things up.
To enable developer options (and by extension, USB debugging), go to SETTINGS>>ABOUT TABLET>>scroll down to BUILD NUMBER... on BUILD NUMBER, tap 7 times. You will see a 'toast' message that says something like "Congratulations, you are now a developer!". (If only it where that easy, eh).
Anyway, with Developer Options now enabled (which you should now find in SETTINGS), USB debugging can now be turned on.
Incidently, I've just seen a new option in Developer Options, called Process Stats - Geeky stats about running processes. I'm pretty sure this is new to KitKat, as I've never seen it before. Anyway, tapping on it does indeed yield some stats... which are interesting... Google however, consider them geeky. The implication being that anybody interested in such things is a geek. I just found it humorous, the use of the word geek by Google.
Humorous allusions aside about whether everybody on XDA is actually a geek...or not... I hope this helps.
Rgrds,
Ged.

Just wanted to say how grateful we are for having you gedblake here in n7 forum while this thread doesn't apply to me I still read it and was pleased to see the well written well explained replies.
Don't mean to hijack this thread or for it come over as all gushy etc but than you.:thumbup::beer:
Sent from my C5303 using xda premium

Meshe said:
Hi guys,
I've been having problems to update to 4.4 in the Nexus 7 wifi version, the only thing I done is unlock the bootloader and root, once I tried the OTA upgrade it starts the process and then it shows up the Android little guy with an error, and doesn't shows the error of installation. I tried once the flashing the zip file using TWRP and it just failed. After the first failed the tablet just started to lag horribly. Any suggestions on how to fix this?
Sent from my Nexus 7 using xda app-developers app
Click to expand...
Click to collapse
Hey Ged, do you know any about my issues or suggestions? The 4.4.2 ota upgrade showed up and it too failed to upgrade from 4.3
Sent from my LT26ii using xda app-developers app

Meshe said:
Hi guys,
I've been having problems to update to 4.4 in the Nexus 7 wifi version, the only thing I done is unlock the bootloader and root, once I tried the OTA upgrade it starts the process and then it shows up the Android little guy with an error, and doesn't shows the error of installation. I tried once the flashing the zip file using TWRP and it just failed. After the first failed the tablet just started to lag horribly. Any suggestions on how to fix this?
Sent from my Nexus 7 using xda app-developers app
Click to expand...
Click to collapse
Meshe said:
Hey Ged, do you know any about my issues or suggestions? The 4.4.2 ota upgrade showed up and it too failed to upgrade from 4.3
Sent from my LT26ii using xda app-developers app
Click to expand...
Click to collapse
It could be a TWRP problem...
Hi, Meshe...
You don't state which version of TWRP you're using, and what (if any) errors where displayed when the OTA aborted. If, as you say, you have performed no significant modifications to your Nexus 7, other than unlocking the bootloader and flashing TWRP (and rooted it)... then the 4.4.2 OTA should flash...
...however, there seems to be something odd about the behaviour of TWRP v2.6.3.1.
To elaborate... there is a known problem using TWRP 2.6.3.1 when flashing franco's latest kernel. See here for details on this.
This problem seems to relate to TWRP v2.6.3.1 itself, and not to franco's kernel .zip. The kernel flashes without problems using an earlier version of TWRP, namely v2.6.3.0 and also with the latest CWM recovery...
Nobody seems to know why TWRP v2.6.3.1 fails to flash franco r76, but fail it does. It appears that something is 'broken' in TWRP v2.6.3.1.
So I'm suspecting that your difficulties flashing the KitKat OTA might be similarly related to whatever is broken in TWRP v2.6.3.1... assuming of course, that this is the version you're currently running.
-------------------------------------------------
Here's what I would do... flash either TWRP v2.6.3.0 (the previous version) or CWM v6.0.4.3 (links below), and try flashing the KitKat OTA again. (I used CWM when applying the KitKat 4.4.2 OTA and it flashed without problems).
TWRP Recoveries...
http://techerrata.com/browse/twrp2/grouper
http://techerrata.com/browse/twrp2/tilapia
ClockWorkMod Recoveries...
http://www.clockworkmod.com/rommanager
(It's important you get the correct version of CWM recovery for your Nexus 7, as there are four CWM recoveries listed for the Nexus 7; two for the first generation model, and two for the second generation model.)
You'd normally fastboot flash a custom recovery, but if you're already rooted, you can flash a custom recovery directly from the Nexus 7 itself, without going anywhere near a PC... by using the rather excellent flashify app.
To summarize...
1). Install flashify on the Nexus 7.
2). Download to your Nexus 7 any custom recovery other than TWRP v2.6.3.1.
3). Ensure the KitKat 4.4.2 OTA update .zip is located somewhere on the Nexus 7.
-----
4). Use flashify to flash the custom recovery (It will request root privileges).
5). Boot (via the bootloader) into your custom recovery.
6). Using that custom recovery, flash the OTA... again.
Finally, if the above doesn't work, and the OTA aborts again, write down any error messages that are displayed. They can sometimes prove invaluable in diagnosing the problem, in order to decide what the next step is to take. Whenever I embark upon some project, for which taking screenshots isn't an option, I always keep my camera handy, such that I can take photographs of the screen... affording me a complete photographic record of the process, errors included, that I can review later. Very useful when things go wrong... as sometimes they do.
Hope this helps... and good luck.
Rgrds,
Ged.

zolaisugly said:
Just wanted to say how grateful we are for having you gedblake here in n7 forum while this thread doesn't apply to me I still read it and was pleased to see the well written well explained replies.
Don't mean to hijack this thread or for it come over as all gushy etc but than you.:thumbup::beer:
Sent from my C5303 using xda premium
Click to expand...
Click to collapse
Wow, erm, I mean yes... thanks... @zolaisugly... not quite how to respond to that.(blushing/embarrassed).
But thank you for your kind words, they're hugely appreciated.
I just try to help as best I can... 'cos I know what it feels like when you think you're 'bricked' or otherwise have problems with your device, as I had last year, with my (the then new) Nexus 7....and it's a uniquely horrible feeling.
You can read about my fumbling efforts here.
But it was posts here on XDA that got me back on track... and got my Nexus 7 working again.
So now, I try to give something back to XDA... my way of saying thanks I guess... and always I remember the stress I went through back in November of last year with my Nexus 7... so I can empathise with those who might not be so knowledgeable, or confident, or sure of their own capabilities, as some of the more experienced XDA veterans. And I try to help... when and where I can. Nobody can know everything... and everybody begins somewhere.
--------------------------------------
To all...
The primary rule I've learned in this past year, is if you think you've bricked your Nexus 7, or have some other seemingly intractable problem, is...
--- DON'T PANIC ---
Panic is an emotional response, and is the enemy of logical, rational thought.
It clouds good judgement... and may lead you to make BAD DECISIONS. Which will likely lead you to make a BAD SITUATION... WORSE.
Don't make any rash, uninformed decisions. It's understandable you want to get your Nexus 7 working again... but do some research first. Review your options. Read... and understand what you're doing... before you do it.
Carpenters and people who work with wood, have an old saying...
~ "Measure twice, cut once." ~
This axiom, I feel, is just as true and applicable to technology as it is to making chairs, tables and putting up a set of shelves.
Use XDA... If you've got a given problem, chances are good, somebody has had it before you, or has it now. A solution may already have been posted.
Use the XDA search engine... or go to Google search, and type "XDA ..." followed by some keywords that distill the essence of your problem.
I've never known Google search to NOT display something that might be pertinent to an Android problem... and usually it's almost always XDA that comes at the top of the Google search results.
--------------------------------------
Right... I'll shut 'up now.. I've waffled on far too long. And I don't want to earn the ire of the moderators for taking this thread wildly off topic.
Rgrds,
Ged.

GedBlake said:
Wow, erm, I mean yes... thanks... @zolaisugly... not quite how to respond to that.(blushing/embarrassed).
But thank you for your kind words, they're hugely appreciated.
I just try to help as best I can... 'cos I know what it feels like when you think you're 'bricked' or otherwise have problems with your device, as I had last year, with my (the then new) Nexus 7....and it's a uniquely horrible feeling.
.
Click to expand...
Click to collapse
OK well if you don't mind I'd like to pick your brain too . I am without a doubt no stranger to Android, rooting, custom roms, and so on, however this is my first experience with the nexus 7 (or with tablets in general for that matter), so there's just a couple of things I'd like to clarify if possible. I recently got a great deal on a 2012 32gb Nexus 7 WiFi, but I guess one reason why it was a great deal is because it came with 4.1.2 lol. So I have successfully unlocked the bootloader, rooted it, and flashed cwm recovery to it using wugs toolkit (what a great tool by the way!), and I originally assumed from this point on that I'd just be flashing custom roms like normal. After reading around for awhile I guess I must've confused myself, because now I'm not really sure what the "best" route to take would be anymore. First of all would I really need to flash every ota and build all the way up to 4.4.2 like described earlier? I found another thread that shows how to extract the boot, system, and bootloader images from the 4.4.2 ota off of Googles site, and then you could use wugs toolkit to flash them without losing data, would that work though considering I'm only on 4.1.2? Or should I just do all of the ota updates that pop up until I'm up to 4.4.2? I guess what I'm asking is what would be the best and or easiest way to get from 4.1.2 all the way to 4.4.2? I'm not concerned about losing data whatsoever just to clarify because I just got this so I haven't done hardly anything with it yet. I'm just under the impression that I can't even flash a 4.4 custom rom considering how old the version is on this, but I'm not sure if that's even correct or not.Anyway I'd really appreciate any insight or suggestions you might have because the last thing I want to do is rush into something and cause twice the work for no reason lol.

jeep447 said:
OK well if you don't mind I'd like to pick your brain too . I am without a doubt no stranger to Android, rooting, custom roms, and so on, however this is my first experience with the nexus 7 (or with tablets in general for that matter), so there's just a couple of things I'd like to clarify if possible. I recently got a great deal on a 2012 32gb Nexus 7 WiFi, but I guess one reason why it was a great deal is because it came with 4.1.2 lol. So I have successfully unlocked the bootloader, rooted it, and flashed cwm recovery to it using wugs toolkit (what a great tool by the way!), and I originally assumed from this point on that I'd just be flashing custom roms like normal. After reading around for awhile I guess I must've confused myself, because now I'm not really sure what the "best" route to take would be anymore. First of all would I really need to flash every ota and build all the way up to 4.4.2 like described earlier? I found another thread that shows how to extract the boot, system, and bootloader images from the 4.4.2 ota off of Googles site, and then you could use wugs toolkit to flash them without losing data, would that work though considering I'm only on 4.1.2? Or should I just do all of the ota updates that pop up until I'm up to 4.4.2? I guess what I'm asking is what would be the best and or easiest way to get from 4.1.2 all the way to 4.4.2? I'm not concerned about losing data whatsoever just to clarify because I just got this so I haven't done hardly anything with it yet. I'm just under the impression that I can't even flash a 4.4 custom rom considering how old the version is on this, but I'm not sure if that's even correct or not.Anyway I'd really appreciate any insight or suggestions you might have because the last thing I want to do is rush into something and cause twice the work for no reason lol.
Click to expand...
Click to collapse
Hi, jeep447...
You're quite welcome to 'pick my brain', as you put it... but don't be too surprised if all you find in there is an oily rag, a half eaten sandwich and a dead D cell battery.
I'm by no means an Android expert; there are far more knowledgeable posters here on XDA... and they appear to be in possession of secret arcane Android knowledge, that is beyond my understanding.
However, I will try to help insofar as my knowledge allows. On to your question(s)...
First things first... if you're currently running Jellybean 4.1.2 on the device, then I think it would be a good idea to bring it up to date to KitKat 4.4.2 first... before you start flashing Custom ROMs.
Theoretically, it shouldn't make any difference if you where to flash a Custom ROM now, without bringing it up to date. But there might be an issue with the bootloader...
...which Custom ROMs WILL NOT update.
The bootloader can only (as far as I know) be updated by either...
-------------------------------------------------------
a) Allowing an Android update via the normal update route (or manually flashing the OTA yourself in recovery).
...or...
b) Fastboot flashing the full factory image that contains the new bootloader.
-- (however, see my Addendum toward the end of this post).
-------------------------------------------------------
I am not aware of any Custom ROMs that go anywhere near the bootloader partition. Which is probably a good thing actually, since a bad or incorrect bootloader flash has the potential for HARDBRICKING the Nexus 7.
My recollection is a little hazy... but I think with Jellybean 4.1.2, the bootloader was at version v4.13... since then, there have been two bootloader updates, v4.18, and the current version, which stands at v4.23.
You can check which bootloader you're currently on by booting into the bootloader as follows... shutdown the Nexus 7 completely. Press and hold the VOL DOWN button, whilst holding, press the POWER ON button. The Nexus 7 should now boot into the bootloader. On the lower left hand side of the screen, in a tiny font, you should find (amongst other things), the bootloader version number.
Now all of this detail about bootloaders might not matter... you could happily flash some new Custom ROM... and it might work without any problems with an old bootloader... but, on the hand, it might not.
So, I think, before you try tinkering around in the Custom ROM area... and If I where you, I would bring the Nexus 7 completely up to date, running Android 4.4.2 build KOTH49H (and the latest bootloader... v4.23).
The easiest and arguably the safest way of doing this, is to just allow the OTA updates normally, as and when they appear in the notification bar. Or, alternatively go to SETTINGS>>SYSTEM UPDATES > > and tap the CHECK NOW button. This is the method by which 99.9% of all Android users get their updates...
...and which is how I initially updated mine...in November of last year, when I first got my Nexus 7.
Running Jellybean 4.1, straight out of the box, once I connected it to mains power (updates won't occur if your battery is below a certain percentage), and acquired a WiFi signal... my Nexus 7 went through 3 or 4 reboots, upgrading from Jellybean 4.1 to Jellybean 4.1.1 to Jellybean 4.1.2 to Jellybean 4.2 (which introduced the world to Googles new and improved 11 month calender!). In December, Jellybean 4.2.1 was released, in time for Santa to arrive, which restored the missing month, December, in the date-picker.
Your succession of updates will be noticeably longer, as since then, we've had Jellybean 4.2.2, Jellybean 4.3, KitKat 4.4, and finally KitKat 4.4.2.
Along the way, with these updates, your bootloader will also be updated, silently and without you being notified of the fact. Most Nexus 7 owners are probably not even aware of the bootloader, much less if the latest OTA has updated theirs. So, the bootloader is not something you would need to normally flash directly yourself.
Of course there's nothing to stop you applying the OTA updates manually yourself, as I've written about here.
However you 'take' the updates, OTA's won't cause you to loose data... all your apps will still be there, as will your pics, videos and music files.
One last point concerning OTA updates... whether applied normally, or flashed manually... you will loose your Custom Recovery (in your case CWM)... and if you're rooted, you'll loose that as well... but it's easy enough to get both back after the update.
-------------------------------------------------------
Once your Nexus 7 is completely up to date, running KitKat 4.4.2, and before you do anything else, I recommend you make a Nandroid backup. I find it vaguely astonishing that so many people seem to miss this (IMHO) critical step.
Once you have a Nandroid backup under your belt... you can pretty much flash any Custom ROM or Kernel, safe in the knowledge that should anything go wrong with the flash, you can restore back to the point you where at before you flashed that ROM/Kernel or other 'mod'.
In fact, I don't think it would be a bad idea for you to create one now... whilst still running Jellybean 4.1.2... using your recently installed version of CWM.
Nandroid backups, whether created with CWM or TWRP, are a bit like 'restore points' in Windows... and I just think it's good practice and common sense, to have at least one good Nandroid backup stored on the device... before you start flashing stuff.
-------------------------------------------------------
Right... I think that covers most of your questions.
I'll try to keep an eye on this thread... in case you have any followup questions.
But I'm going to be pretty busy over the next week or so, what with Christmas on the horizon... so I may not respond immediately.
Good luck with your new Nexus 7... and, as ever... I hope this helps.
**********
Addendum
I've spoken at length about bootloaders and OTA updates. And I think this is your best and least risky way of bringing your Nexus 7 up to date.
Whist there is now available a full factory image for KitKat 4.4.2 build KOTH49 (see my sig for download links), I would avoid it at this time.
Apart from the fact it will completely wipe you're Nexus 7 (which is normal and to be expected) ... the STOCK FACTORY IMAGES, and the bootloaders that ship with them are currently in a bit of a mess. .. and may cause HARDBRICK.
See this thread for further details on this...
[WARNING][URGENT] N7 grouper (2012 WiFi) bootloader .img files from Google.
There are ways of working around this; (you need the bootloader from Build JWR66V)...
...but I suggest you stick with OTA's for now, to bring your device up to date...
Or at least until either Google sort out the 'dogs breakfast/pigs ear' they've made of the factory images... or until you've acquired sufficient knowledge and confidence in modifying a FACTORY STOCK image, such that it fastboot flashes a known GOOD BOOTLOADER.
Rgrds,
Ged.""

Kill the kill switch - "ST - yy"

< include generic disclaimer here >
TL;DR
Since update 3.1, Nvidia can force updates (such as the one that bricks your tablet) to be downloaded and installed silently. No guarantees, but:
If you're on stock, delete TegraOTA (/system/app/TegraOTA or /system/priv-app/TegraOTA if you're on 5.0 or newer, or /system/app/TegraOTA.apk if you're still on 4.4) before booting into Android (the attached ZIP file does this for you, but please check with the file manager in recovery before rebooting and let me know if it didn't work), then reboot
Note: you also will need to delete TegraOTA again if you ever install an OTA from Nvidia or a recovery image
If you're not on stock, you're probably safe
EDIT: The urgent OTA is currently not getting sent out to any devices anymore, not even to those who have been getting it before.
EDIT 2: The urgent OTA is now being delivered again, this time named "ST - yy"!
What if my tablet is already deactivated?
Unless you can still boot into fastboot mode (in which case your tablet isn't really deactivated yet), your tablet is probably gone for good. The only way to fix this would be through nvflash, and using it requires the SBK that is unique to each device and that only Nvidia knows, so it's pretty unlikely that we'll ever be able to fix these deactivated tablets.
What/why/how?
In the last OTA (Update 3.1), Nvidia has made some changes to their TegraOTA application. The most important/interesting/suspicious of which is the ability for them to mark OTAs as "urgent". What this means is that these updates will be downloaded without ever notifying the user, and they will be installed without asking the user for permission first. If this is how the kill switch is delivered, all users will see is the tablet randomly rebooting and installing an update, then the tablet would never boot again. As some of you might notice, this would match what has been happening to a few users already, both here and on reddit.
But that's not all. I've been connecting to the OTA servers using various serial numbers (both found and provided to me by a few people) in hopes of actually finding the update that bricks the device. The first serial number I've tried that wasn't mine was the serial number from the screenshot on the recall page. It revealed an interesting "urgent" OTA, named "SHIELD Tablet xx - LTE", which does nothing but flash a blob (which, among other things, contains the bootloader). Many more questions appear now, but the main one is: if this is nothing but a routine bootloader update, why is it marked urgent? And why is it not attached to any Android update? But this by itself is not enough to prove anything, as I could only obtain it with one serial number, so as far as I could have known, it might had just been an internal update or something similar. (update is linked and analysed in the second post below)
Today, however, one of the serial numbers I've been given by some of the people here (thanks for the help guys!) turned out to have the same update waiting for it the next time it connected to the Internet. This rules out the possibility of an internal update, so the next somewhat obvious possibility is that this is the kill switch. Mind you, I still have no direct way of proving this without flashing the ZIP to see what happens (which I'm not planning to do myself), but I will keep checking on the other serial numbers I've gotten to see if this update turns up for them too.
The same person who has given me this serial number has also tested running the old tablet on the latest stock Android version but with TegraOTA removed, and, as expected, the tablet is still working perfectly fine now. Your mileage may vary.
How can I know if the kill switch has been triggered for my tablet?
Go to http://shield.bogdacutu.me/ and enter the full serial number of your old tablet. If the next OTA returned is "SHIELD Tablet xx" "ST - yy", the kill switch has been triggered for your tablet.
Warning: the serial number from the box of the tablet and the one etched on the side of the tablet are not complete, as they only contain the first 13 characters of the full (20 characters) serial number. You can get the full serial number from Android (Settings -> About -> Status), from the bootloader (it will be on the screen when you boot into bootloader mode), or from your computer if the tablet is or (in some cases) if it was previously connected, using various tools such as USBDeview. Example: 0413714803249000a4cf (you can try this on the page and it will return that the kill switch is activated).
Why would I want to also do the fix on my new tablet too?
The update is signed by Nvidia, and communication with the OTA server does not use HTTPS, so, for example, a malicious WiFi network could MITM your connection and cause this update (as well as any other signed update) to be flashed to your new tablet without your permission, thus permanently disabling it too. If you have the stock recovery, only updates signed by Nvidia can run. The story might be slightly different if your recovery doesn't enforce signature verification (such as TWRP and CWM by default).
Can I still get updates from Nvidia after doing this?
Not directly, but people will post OTA download links here on xda when new updates get released. I'd personally recommend that you wait before flashing though until someone here checks the new update to confirm that there's no new way for Nvidia to kill your tablet.
Many hours of work have gone into investigating this. Even if it doesn't help your specific scenario, consider hitting that Thanks button, so that I can at least know it wasn't for nothing.
I'd also like to thank the people who have given me their serial numbers to use for testing again, this wouldn't have been possible without their help: @Beauenheim, @Jackill, and @runandhide05 (who has even volunteered to test removing TegraOTA with the latest update on his old tablet :highfive

Fragments of code from TegraOTA.apk
< screenshots temporarily removed >
Also, from what I've seen so far, the update isn't delivered instantly after activating the new tablet. I don't know exactly what the rule is, but out of the 4 serial numbers that I have, only 2 have this update waiting for them.
EDIT: One more serial number from the ones I have has gotten the xx update. Only one left...
EDIT 2: All the serial numbers I have have the urgent OTA waiting for them now.

"SHIELD Tablet xx" - Update Analysis
OTA URL: http://ota.nvidia.com/ota/data/post...wf-full_ota-32256_554.0168.20150624152335.zip
yy OTA URL: http://ota.nvidia.com/ota/data/posted-roms/uploaded/st---yy--092704233775---7294.20150819152732.zip (if you don't know what you're doing, DO NOT DOWNLOAD THIS, it's very likely that this will permanently brick your device upon flashing it!!!) - also attached to this post in case this link becomes invalid
updater-script is the first file we check:
Code:
getprop("ro.product.device") == "shieldtablet" || abort("This package is for \"shieldtablet\" devices; this is a \"" + getprop("ro.product.device") + "\".");
nv_copy_blob_file("blob", "/staging");
reboot_now("/dev/block/platform/sdhci-tegra.3/by-name/MSC", "");
Suspiciously enough, this only flashes a blob to the staging partition. But what exactly does this blob do, you might ask? Well, the blob actually contains data for 9 partitions, which are automatically replaced during the next boot (before the bootloader does anything else at all, so once you've rebooted, there's no going back) with the contents present in this blob. The 9 partitions are as follows (also detailing comparison with files from update 3.1):
BCT (Boot Configuration Table) - stores some information that is needed for the device to find the bootloader stored on the other partitions, initialize the RAM and some other stuff
Status after update: probably corrupted - the previous OTAs have binary BCTs, but this update replaces it with a text file (which, while it does contain somewhat relevant information, is likely not a valid format). If this is corrupted, it's enough for the device not to be able to boot anymore.
BMP (boot logo) - intact
DTB - intact
EBT (part of the bootloader) - has a zeroed out region
NVC (part of the bootloader) - intact
RBL (part of the bootloader) - has a zeroed out region
RP4 (landscape boot logo) - intact
TOS (Trusted OS - probably part of the bootloader too) - has a zeroed out region
WB0 (related to the boot process, source file is named "nvbootwb0.bin") - has a zeroed out region
The update also contains a few other files, but those are not used at all (probably leftovers from the 5.1 AOSP update template that they are using).
DO NOT DOWNLOAD THE ATTACHMENT IF YOU DON'T KNOW WHAT YOU'RE DOING. THIS IS THE XX OTA, NOT THE ZIP THAT REMOVES TEGRAOTA!

Just as I suspected!!

Thanks a lot this is great. So the silent updater can force updating even with a custom recovery like cwm?
How to install the provided zip?
Thanks again.

tecnoworld said:
Thanks a lot this is great. So the silent updater can force updating even with a custom recovery like cwm?
How to install the provided zip?
Thanks again.
Click to expand...
Click to collapse
CWM and TWRP are both compatible with OTAs, so yes, it can. If you completely erase the recovery (fastboot erase recovery), the update can't get flashed, but the tablet will still reboot (which is at least annoying).
You can flash the provided ZIP through CWM or TWRP (but please check through the file manager if /system/app/TegraOTA still exists after installing it, the ZIP hasn't gone through a lot of testing so it might not work properly in all cases)

tecnoworld said:
Thanks a lot this is great. So the silent updater can force updating even with a custom recovery like cwm?
How to install the provided zip?
Thanks again.
Click to expand...
Click to collapse
This was to be my question too... Normal ota updates will not flash if you have a custom recovery, so how would this silent ota update?

bluegizmo83 said:
This was to be my question too... Normal ota updates will not flash if you have a custom recovery, so how would this silent ota update?
Click to expand...
Click to collapse
Normal OTAs don't work through custom recoveries because they do various checks that usually fail when you have a custom recovery (such as if the system partition is modified, by rooting for example), this urgent OTA has none of those checks

Bogdacutu said:
Normal OTAs don't work through custom recoveries because they do various checks that usually fail when you have a custom recovery (such as if the system partition is modified, by rooting for example), this urgent OTA has none of those checks
Click to expand...
Click to collapse
Oh ok! Great explaination. Thanks for all your hard work on this! I'm flashing the zip now, i'll report back if it removes the file
Edit: Ok I flashed the zip, and TegraOTA is gone. Now I will finally turn on my new tablet and set it up!

So out of interest, what do you think the chances are that thisll work?
How did you find out if the update is waiting? FYI I flashed the ZIP... All is good and it booted fine on LTE 32Gb...
Plus the deleting of the TegraOTA File has gone through... So you really think the TegraOTA removal has stopped it?
How do i check if i have downloaded randomly that update?

Great post. Hopefully that's as far as Nvidia is going to go. I flashed a custom rom on my old tablet. I'm keeping my new one stock but deleting the system app per your post. Just in case Nvidia is spiteful when I don't return the old tablet. I don't want to leave them any option of nuking the new one.

fkofilee said:
So out of interest, what do you think the chances are that thisll work?
How did you find out if the update is waiting? FYI I flashed the ZIP... All is good and it booted fine on LTE 32Gb...
Click to expand...
Click to collapse
Decompiled the OTA application. Using information from there I can connect to the OTA server directly from my PC, and request updates for any given serial number and Android version combination.
I wouldn't have posted this if I weren't relatively confident in my findings

Bogdacutu said:
Decompiled the OTA application. Using information from there I can connect to the OTA server directly from my PC, and request updates for any given serial number and Android version combination.
I wouldn't have posted this if I weren't relatively confident in my findings
Click to expand...
Click to collapse
I know fella I appreciate it. Could you check my second point? 2 x Nvidia Shields would be awesome! One for Work, One For Home

fkofilee said:
Plus the deleting of the TegraOTA File has gone through... So you really think the TegraOTA removal has stopped it?
How do i check if i have downloaded randomly that update?
Click to expand...
Click to collapse
Yes, I think it did. If that update was downloaded on your device, it would have been too late (as it reboots instantly after the update is downloaded), so I wouldn't worry about that.

Bogdacutu said:
Yes, I think it did. If that update was downloaded on your device, it would have been too late (as it reboots instantly after the update is downloaded), so I wouldn't worry about that.
Click to expand...
Click to collapse
So heres an interesting one for you, using a logical mindset, if you receive your new tablet, activate it, the next time that the old one connects to the network, it downloads this update and bricks it? But it wont technically do this until the new tablet is turned on?

fkofilee said:
So heres an interesting one for you, using a logical mindset, if you receive your new tablet, activate it, the next time that the old one connects to the network, it downloads this update and bricks it? But it wont technically do this until the new tablet is turned on?
Click to expand...
Click to collapse
As mentioned in the OP, the update doesn't get delivered immediately after you activate the new tablet. But yes, the old tablet shouldn't get the update before the new one is activated.

Bogdacutu said:
As mentioned in the first post, the update doesn't get delivered immediately after you activate the new tablet. But yes, the old tablet shouldn't get the update before the new one is activated.
Click to expand...
Click to collapse
Sorry fella missed that part, I will be donating some funds when i get paid later this month Mucho Gracias!

Totally not related to this thread, but I just went to setup my new tablet and it's not letting me restore apps & settings from my old Shield Tablet... It doesn't show my old tablet as a restore option. I doubt checked and the old tablet is setup to backup all settings and apps though. Anyone else have this issue when setting up they're new tablet?

bluegizmo83 said:
Totally not related to this thread, but I just went to setup my new tablet and it's not letting me restore apps & settings from my old Shield Tablet... It doesn't show my old tablet as a restore option. I doubt checked and the old tablet is setup to backup all settings and apps though. Anyone else have this issue when setting up they're new tablet?
Click to expand...
Click to collapse
Upgrade to 5.1 on the new tablet without restoring any data, then do a factory reset and you should get the option to restore

Bogdacutu said:
Upgrade to 5.1 on the new tablet without restoring any data, then do a factory reset and you should get the option to restore
Click to expand...
Click to collapse
AWESOME man, thank you!!

[SOLVED] Cascading failures leading to bootloop and softbrick

Hello all. I am about done with this phone. Let me give you a quick timeline.
I had a bootloader error, so I flashed the NPN25.137-35 images to get it working
I used it for about 1 week, installing all of the OTA security updates
One morning, my phone had restarted (I know because "You must enter your pattern after a restart")
Over the course of this day, google apps starting force closing and opening some of them would soft reboot the phone.
The next day, random apps were doing it too
Finally, after one crash, the OS never came back up, it was bootlooping
Upon a hard restart, the phone only boots into bootloader.
This is where I am now. I have downloaded NPN...35-5, NPNS...93-10, and NPNS...92.14. Unfortunately, trying to flash any of these give me a "prevaildation failed security update downgrade" error on every partition I try to flash. The phone just bootloops when I try to restart it.
Things I have tried:
Using fastboot to manually install one of the 3 packages mentioned above.
Using a toolkit to automate the install of the 3 packages.
Using Motorola Device Manager (Never got it to launch)
Flashing the blankflash bin (No usable image file found)
Android OEM unlock setting was not set before this crash, so I cannot unlock the bootloader.
Praying to various deities.
Unzipping the packages, editing the *info.txt file into androidinfo.txt and rezipping to use as an update package (Invalid info.txt error)
I have no idea what to do next. I find it frustrating that Motorola doesn't differentiate between 32GB, 64GB, Amazon ads, no amazon ads, US, EU, or indian variant in it's model numbers! Everything is just "XT1687" and none of the update files are named with words, so knowing what the hell I'm flashing is impossible.
So, frustrations aside, does anyone have any suggestions as to how I can get this phone working again. On a side note, the only thing that I can think of that would cause such a cascading failure from Stock OS is RAM or Storage corruption / failing. Any thoughts on that as well?
=~=~=~=~= SOLUTION FOUND =~=~=~=~=
This may not be a good solution for anyone else that has this issue, but recently Oreo came out and the OTA update was captured. I was able to flash the new OTA because it had a higher security level and at least got the phone bootable.

Do you know what software channel you were on? E.g. retus, retla, etc? If your phone was completely up to date with the OTA, then you can't use a firmware version of less than 92-14 or 93-14. Whether or not you use 92 or 93 depends on the channel.
Locked bootloader limits other possibilities unfortunately.

Retus. I can't guarantee it, but that looks familiar to me, like I had seen it somewhere in the "about phone" section. Is there a released Stock image that has the current security patch? I can't find it on XDA and I'm not trusting androidfixfiles.info or a link in a youtube video.

93-14 hasn't been leaked yet. So you'll be stuck for now.

Kilo__ said:
I have no idea what to do next. I find it frustrating that Motorola doesn't differentiate between 32GB, 64GB, Amazon ads, no amazon ads, US, EU, or indian variant in it's model numbers! Everything is just "XT1687" and none of the update files are named with words, so knowing what the hell I'm flashing is impossible.
So, frustrations aside, does anyone have any suggestions as to how I can get this phone working again. On a side note, the only thing that I can think of that would cause such a cascading failure from Stock OS is RAM or Storage corruption / failing. Any thoughts on that as well?
Click to expand...
Click to collapse
As a last resort you might try booting TWRP in fastboot mode, download and flash the TWRP flashable version of NPNS25.137-93-14. and see if that gets you back to a working phone. Just a suggestion. I don't know if it will boot when the bootloader is locked but it is worth a try.

pastorbob62 said:
As a last resort you might try booting TWRP in fastboot mode, download and flash the TWRP flashable version of NPNS25.137-93-14. and see if that gets you back to a working phone. Just a suggestion. I don't know if it will boot when the bootloader is locked but it is worth a try.
Click to expand...
Click to collapse
The phone was completely stock. It has the stock recovery and bootloader.

Kilo__ said:
The phone was completely stock. It has the stock recovery and bootloader.
Click to expand...
Click to collapse
I get that. What I am suggesting is not installing TWRP, but booting it from fastboot, if it is even possible. Given your results trying to flash a ROM I would say not. But what do you have to lose by trying?

pastorbob62 said:
I get that. What I am suggesting is not installing TWRP, but booting it from fastboot, if it is even possible. Given your results trying to flash a ROM I would say not. But what do you have to lose by trying?
Click to expand...
Click to collapse
I've tried that with a locked bootloader myself, it doesn't allow a non-signed image to boot. OP should give it a go as a 'hail Mary' attempt, but I wouldn't be holding my breath.

I've never heard of a phone that was fully stock with no mods or flashing ever done on it getting a bootloader error. The only bootloader error I am aware of is when the bootloader and ROM build are mismatched which doesn't happen unless the phone is being manually flashed. Was the phone on a custom ROM and you tried to return to full stock? Did you purchase the phone used?
If no to both exactly what did you see when you got the bootloader error? What was the message and what was the phone doing?
People who are on full stock with a locked bootloader don't usually flash system images so your story is a little hard for me to understand unless there is more to it. Normally a factory reset would be the logical solution when your phone is acting odd--flashing a system image seems pretty extreme and it sounds like flashing the wrong system image might be the cause of your current problems.

jhs39 said:
I've never heard of a phone that was fully stock with no mods or flashing ever done on it getting a bootloader error. The only bootloader error I am aware of is when the bootloader and ROM build are mismatched which doesn't happen unless the phone is being manually flashed. Was the phone on a custom ROM and you tried to return to full stock? Did you purchase the phone used?
If no to both exactly what did you see when you got the bootloader error? What was the message and what was the phone doing?
People who are on full stock with a locked bootloader don't usually flash system images so your story is a little hard for me to understand unless there is more to it. Normally a factory reset would be the logical solution when your phone is acting odd--flashing a system image seems pretty extreme and it sounds like flashing the wrong system image might be the cause of your current problems.
Click to expand...
Click to collapse
I agree. :good:

While my phone was wholly stock, I am not new to phone rooting or custom ROMS. I bought the phone from someone who was trying to unlock it. They screwed something up and couldn't get the phone to boot. I bought it, flashed the NPN25.137-35 image after reading plenty of XDA posts about it. This one was the Retus / North America stock image. Flashed using the suggested guidelines that are along the lines of "fb_oem_mode ... flash oem oem.bin ... flash partition sparsechunk1.img" (Something like that). That got it running and once booted, it had many OTAs update in quick succession. After about a week the phone started having trouble. Google apps would crash frequently, then non-google apps started crashing and restarting my phone. After one said restart, the phone would only bootloop. I tried rebooting into recovery to do a factory reset and got the bootloader instead. I can go take a look at the bootloader and see if it says it's secure / oem or what

Kilo__ said:
While my phone was wholly stock, I am not new to phone rooting or custom ROMS. I bought the phone from someone who was trying to unlock it. They screwed something up and couldn't get the phone to boot. I bought it, flashed the NPN25.137-35 image after reading plenty of XDA posts about it. This one was the Retus / North America stock image. Flashed using the suggested guidelines that are along the lines of "fb_oem_mode ... flash oem oem.bin ... flash partition sparsechunk1.img" (Something like that). That got it running and once booted, it had many OTAs update in quick succession. After about a week the phone started having trouble. Google apps would crash frequently, then non-google apps started crashing and restarting my phone. After one said restart, the phone would only bootloop. I tried rebooting into recovery to do a factory reset and got the bootloader instead. I can go take a look at the bootloader and see if it says it's secure / oem or what
Click to expand...
Click to collapse
Try flashing just the stock recovery, as it sounds like that is corrupt. Ideally you'd want to get a recovery that was the same build as you were on after all the OTAs had installed. At least you'd hope that that would give you the factory reset option.
If that doesn't work, there's fastboot commands to erase user data, cache, which would be pretty much what a factory reset would do. Hope you had your data backed up.

Oreo OTA came out recently. Someone grabbed the update file and uploaded it. I was able to flash it and get the phone to boot. The verdict is still out on if it'll be stable.