Database Users

Nexus 7 Stuck in Boot Animation Loop--Please Help

***TL;DR AT THE BOTTOM***
*^*EDIT 2!!*^*
Utilizing Cerberus, I was able to get passed the boot animation into the lock screen, though the Launcher is, for all intents and purposes, nonexistent. However, I was able to install Nova Launcher and can go to a home screen just fine. THIS IS NOT SATISFACTORY. I want to get back to STOCK Launcher, but it apparently does not exist anymore. I've managed to copy over my backup of Launcher2.apk, but it still refuses to acknowledge its existence. Can I get an update.zip that'll reinstall the default launcher from someone? I can boot into recovery via ROM Manager now I suppose!
+++EDIT!+++
+++~~~I have discovered that my problem is not the device being stuck in boot up, but that the boot animation will not cease--as +in the device is actually powered on, just displaying the boot animation like a screen saver. I cannot boot into recovery as I get +the Google splash screen and it never goes anywhere, my bootloader is freezing every time I plug it into my computer, and the +drivers will not install. My computer cannot detect fastboot and I can't connect to the Nexus via adb either. I CAN access internal +storage but that's about the extent of what I can do.+++~~~
Long version:
I decided I wanted to change the App Drawer icon from stock to a Nexus X that inverted its colours when pressed. I found the icon, converted it to png, inverted the colours and everything was going fine.
After a while I finally managed to find the right icons to replace in the system apk file "launcher2.apk". "ic_allapps.png" and "ic_allapps_pressed.png" or something very similar. I simply replaced them with my two icons, installed my modified launcher2.apk, and that was it.
Immediately, my home wouldn't open at all, no matter how many times I pressed the home button. It just would not exit the app I had up. So I started backing and ended up in an infinite back loop. I powered off the device, waited a minute, and powered it back on.
It came to the usual "Google" screen with the unlocked symbol at the bottom, no problems. However, then it started playing the boot animation. The boot animation never stopped. It looped infinitely. I tried resetting the tablet a few times for the same result. It was after 3 am and I had to get up for work in 4 and a half hours. I thought that maybe it was gonna take a while. So I flipped the Nexus over while it was "booting up" and went to sleep.
When I woke up and checked the tablet at 7:30, it was STILL booting up. Obviously I had screwed something up.
Now, stupid me, I had never flashed CWM recovery on my Nexus 7 (haven't had it that long), so all I'm stuck with is STOCK Recovery. I'm pretty sure I can rescue the Nexus by factory resetting it or something similar, but I'd rather try to save it first. All I modified was a LAUNCHER application, so I'm pretty sure the current state of the Nexus itself shouldn't be too far gone. Is there any way to save the Nexus WITHOUT a data wipe? And if the data wipe DOESN'T fix my problem, is it possible to somehow flash a stock ROM through stock Android Recovery?
***TL;DR***
I modified launcher2.apk and replaced "ic_allapps.png" and "ic_allapps_pressed.png" with two customized .png files (which I renamed to their appropriate file names). Now my Nexus is stuck on the boot animation indefinitely. I would like to save all of my data, as a data wipe would be inconvenient, but if I must do one I shall. I am on a stock ROM and a stock Recovery. If a data wipe/factory reset will not save my device, is it possible to flash a stock ROM through regular Android Recovery?
===Related but irrelevant to the problem===
Is it completely impossible to change the stock App Drawer icon to something different? I'd rather not have to get a different launcher app just to create a Nexus theme! I did a little more research and found that I should've modified the "all_apps_button_icon.xml" file as well, but I have NO idea how to do that.
Many thanks,
VonDerThWood.

As long as you can get into the bootloader you can flash back to stock using fastboot and the image from here

NeoMagus said:
As long as you can get into the bootloader you can flash back to stock using fastboot and the image from here
Click to expand...
Click to collapse
no need to flash back to stock, silly advice. just flash a custom recovery and flash a stock rooted rom. flashing a stock rooted rom will replace what you messed up on. dont wipe.

simms22 said:
no need to flash back to stock, silly advice. just flash a custom recovery and flash a stock rooted rom. flashing a stock rooted rom will replace what you messed up on. dont wipe.
Click to expand...
Click to collapse
How can I reflash the ROM on stock Android recovery? Googling that returns CWM results.

He is suggesting you flash custom recovery with fastboot and just flash over top of what you did thru the custom recovery which you can do as well, what I suggested just returns it to factory state I don't see whats so silly about it I understand he wants to keep his data but worse comes to worse as long as you can get into the bootloader you're fine

NeoMagus said:
He is suggesting you flash custom recovery with fastboot and just flash over top of what you did thru the custom recovery which you can do as well, what I suggested just returns it to factory state I don't see whats so silly about it I understand he wants to keep his data but worse comes to worse as long as you can get into the bootloader you're fine
Click to expand...
Click to collapse
youre right about if worse comes to worse. reflashing the factory image should be the very last thing to do, when all other options have been tried. im just trying to save his data

If you don't have fastboot set up you might want to give this post a look he describes how to get it set up.
simms22 said:
youre right about if worse comes to worse. reflashing the factory image should be the very last thing to do, when all other options have been tried. im just trying to save his data
Click to expand...
Click to collapse
I don't use custom recoveries and backup my data regularly with Titanium, so restoring after a reflash is really just an afterthought here, to each there own

The problem is not as it seems.
When I plug the Nexus into the computer when in Fastboot mode, it freezes the Recovery. I cannot select anything OR move the selection to anything else. The hell?
I noticed that when the Nexus attempts to boot up, the boot animation gets brighter.
__
Wait, when it attempted to boot up when plugged into my PC, AutoPlay recognized the device as Nexus 7. There is nothing on my screen but the boot animation, however I can browse internal storage.
I cannot, however, connect to it via adb apparently. ADB devices returns nothing.
____
Okay, the problem is NOWHERE near what I thought it was. The boot animation is replacing the lock screen/home screen/everything. I just received an email (I could tell because of the notification noise the tablet made). It is booting up, just not displaying anything passed the boot animation and ADB cannot detect the device. I KNOW it has USB Debugging mode activated and all, but what can I do now?
===
I usually make backups and nandroids but I've barely owned this device. ;P

Does fastboot detect the device?

janedoesmith said:
Does fastboot detect the device?
Click to expand...
Click to collapse
Fastboot doesn't detect the device while booted up like this, and when I plugged it into the computer when in recovery/fastboot mode it not only froze the device, but fastboot wouldn't detect it.
I can get into the internal storage (just not the root of the device unfortunately). So what can one do when he cannot connect to the device via fastboot or adb, nor flash a custom recovery image because he can't access fastboot?
This is getting more complicated the more I dig into it. What the hell did I do?

Are you on the correct screen? I see how you are lumping Fastboot/recovery together, Fastboot is used on the screen with the android with his chest open after holding down the power/vol buttons from complete off , has version info/ unlock status in the lower left.. not sure if you can do that in the recovery but that is where I put the commands in

the freezing in the bootloader is a n7 bug. try a few times. try going into the bootloader then plugging in usb, and try plugging in via usb then going into the bootloader. try a few times, eventually you will get it.

VonDerThWood said:
Fastboot doesn't detect the device while booted up like this, and when I plugged it into the computer when in recovery/fastboot mode it not only froze the device, but fastboot wouldn't detect it.
I can get into the internal storage (just not the root of the device unfortunately). So what can one do when he cannot connect to the device via fastboot or adb, nor flash a custom recovery image because he can't access fastboot?
This is getting more complicated the more I dig into it. What the hell did I do?
Click to expand...
Click to collapse
You have to be in bootloader for fastboot to detect your device. Once in bootloader, open a command prompt where your fastboot.exe is stored and type "fastboot devices" without the quotes. If it detects it, it should list your N7's serial number.

NeoMagus said:
Are you on the correct screen? I see how you are lumping Fastboot/recovery together, Fastboot is used on the screen with the android with his chest open after holding down the power/vol buttons from complete off , has version info/ unlock status in the lower left.. not sure if you can do that in the recovery but that is where I put the commands in
Click to expand...
Click to collapse
Fastboot has the "Recovery mode" option but it just gives me the Google logo with the unlocked icon at the bottom indefinitely...which means I cannot access recovery either? Why didn't I notice this before? >_<
simms22 said:
the freezing in the bootloader is a n7 bug. try a few times. try going into the bootloader then plugging in usb, and try plugging in via usb then going into the bootloader. try a few times, eventually you will get it.
Click to expand...
Click to collapse
Tried 10 times by booting into bootloader first, then 10 times by plugging it in and booting into it while it's plugged in. This is a very...odd bug.
janedoesmith said:
You have to be in bootloader for fastboot to detect your device. Once in bootloader, open a command prompt where your fastboot.exe is stored and type "fastboot devices" without the quotes. If it detects it, it should list your N7's serial number.
Click to expand...
Click to collapse
Nothing at all. Won't detect it or anything.

it is an odd bug. i think every n7 owner who likes to flash roms/kernels has had to deal with it at least once.

VonDerThWood said:
janedoesmith said:
You have to be in bootloader for fastboot to detect your device. Once in bootloader, open a command prompt where your fastboot.exe is stored and type "fastboot devices" without the quotes. If it detects it, it should list your N7's serial number.
Click to expand...
Click to collapse
Nothing at all. Won't detect it or anything.
Click to expand...
Click to collapse
What about in device manager? Does it at least show an unknown device or something similar? Try reinstalling the drivers.

janedoesmith said:
What about in device manager? Does it at least show an unknown device or something similar? Try reinstalling the drivers.
Click to expand...
Click to collapse
Now that I think about it, it DID say something about failing to install an unknown driver the first time I plugged it in. Let me uninstall/reinstall the drivers.
____
After reinstalling the drivers (and removing both of the Nexus7 specific ones), I also removed one named "Android", which, coincidentally, is the driver that the tablet is trying to install upon being plugged in. I have tried to reinstall it several times, but it fails each time, AND I just reinstalled the real Nexus 7 drivers.
___
The Nexus drivers won't reinstall now. I even went to Asus's website and downloaded them, but I have no clue how to install it in this format.
Is there a way to open/install an app through JUST the Internal Storage? If so, I have the stock launcher2.apk file right here...I just need to reinstall it! Damn, how can I get to the Root folder without ADB?

Whoa! Stroke of GENIUS!
I have Cerberus installed on my tablet. Since I know the tablet is booting up, just not displaying passed the boot animation, I decided to give it a try.
I started an alarm, which forced the tablet to the lock screen...I can open apps through the Play Store (as I got an update notification) and the like, but I can NOT get to the home screen.
I opened Total Commander via Play Store, but I can't do anything with it. The app that I used was NinjaMorph and I'm pretty sure the only way I can correct my mistake is through that app. What do I do?
Found NinjaMorph in the Play Store, it couldn't fix my problem. Oh hell.
I tried to copy/replace the launcher2.apk file I screwed up with a backed up one but TotalCommander couldn't do it. It was even granted SuperUser permissions. Attempting with Root Explorer.
Success! I have copied the original Launcher2.apk back into the /system/app folder. HOWEVER, I can NOT install it.
Managed to connect via adb! Things are looking up! Now, how to install this stuff...?
When trying to reinstall the launcher2.apk, it gives me the following error:
INSTALL_FAILED_UID_CHANGED
So I tried uninstalling it to no avail. Troubling.
SO! Now what? I am into the device, and any app I have downloaded through the Play Store is available to me, but I cannot go to the home screen. I need to reinstall the original Launcher2.apk!
Retrying NinjaMorph. It supposedly installed my Launcher2.apk. However, I still cannot return to the Home screen. WTF.
I'm going to install a different Launcher. Hope that works!
Success. I can now return home to Nova Launcher. HOWEVER...
This is not satisfactory. I want my STOCK launcher. Anybody know how I can fix this? The stock launcher is acting like it doesn't exist anymore. Is there a way to just wipe THAT data and keep all the other data on my device?? (Though I admit, I do like how I already was able to change my App drawer icon to my Nexus X <3.)

Edit: I see you resolved it. Good job! I'll just leave this here... :good:
Is there a way to open/install an app through JUST the Internal Storage? If so, I have the stock launcher2.apk file right here...I just need to reinstall it! Damn, how can I get to the Root folder without ADB?
Click to expand...
Click to collapse
You sound to be in Windows driver hell. If you have access to a Linux machine or someone who does, this entire driver mess can be avoided.
You can't install an apk via the MTP or PTP usb interface. You have a few options to fix this, but all depends on getting your drivers sorted.
Otherwise, grab the latest Windows USB drivers from Google - https://dl-ssl.google.com/android/repository/usb_driver_r07-windows.zip and follow these instructions to install them - http://developer.android.com/tools/extras/oem-usb.html
With the drivers installed and the nexus 7 plugged in, try adb devices again. Assuming you can resolve the driver issue, run
Code:
adb install path\to\launcher2.apk

comminus said:
You sound to be in Windows driver hell. If you have access to a Linux machine or someone who does, this entire driver mess can be avoided.
You can't install an apk via the MTP or PTP usb interface. You have a few options to fix this, but all depends on getting your drivers sorted.
Otherwise, grab the latest Windows USB drivers from Google - https://dl-ssl.google.com/android/repository/usb_driver_r07-windows.zip and follow these instructions to install them - http://developer.android.com/tools/extras/oem-usb.html
With the drivers installed and the nexus 7 plugged in, try adb devices again. Assuming you can resolve the driver issue, run
Code:
adb install path\to\launcher2.apk
Click to expand...
Click to collapse
I managed to get ADB working (via adbWireless) after the above post I made, however I cannot get launcher2.apk to install. This time I got the "INSTALL_FAILED_DEXOPT" error instead of the "INSTALL_FAILED_UID_CHANGED" one.

[Q] CM installer bricked my nexus

As the title says, I wanted to try CM installer, and I was on everything stock, not rooted. I downloaded PC, and android programs, followed the instructions, however at one point CM installer on my PC said it cannot communicate with my phone, and it was when it was trying to flash recovery. It said I should try different cable, or USB port, but no luck with either, and now it says my phone is not supported.
I tried to enter recovery, but I only get CM guy and it's stuck, even when I turn off the phone, it turns itself on automatically, and to fully turn it off I need to enter fastboot mode, and then turn off. I tried flashing full stock image (I know how to do that, and I have previous experience on this phone), but my fastboot crashes (Fastboot.exe Has stoped Working), tried to download fastboot again, but nothing helped. I also tried to flash recovery only, and I get the same thing... Also tried to do that with custom recovery, but nothing....
Is there something I can do, or do I need a new phone?
Also, I had like 70% battery when I started, so I am afraid to keep trying, cause if I go out of juice, it's game over, right?

Looks more like issues with your pc communicating with your device, which might have causes other side effects due to that. But I have not tried CM Installer yet.
You should see about getting fastboot working correctly first and getting the right adb/fastboot driver (such as latest Universal Naked Driver, link in my sig). You should also use the latest adb/fastboot .exe from Google, download their latest ADT package. If it still crash, use it on a different machine, if you're on Windows 8 try Windows 7 or Ubuntu.
Also make sure the factory image isn't corrupt, I always have issues downloading it from Google.
Also, I had like 70% battery when I started, so I am afraid to keep trying, cause if I go out of juice, it's game over, right?
Click to expand...
Click to collapse
If the battery goes to 0%, just charge it, do you think everyone throw away their N4 when the battery goes to 0? There is the red light problem, but its an easy fix.

Thanks for answering, I fixed it with a strange method (to me). On CM forum j_cor told me this:
"Your device appears to be stuck in sideload. So the good news is no, you are not bricked. Here is what I would try to do:
1. Boot the device - wait for the "stuck" CM guy to display
2. Plug phone to PC and open a command prompt to the directory to C:\Users\enter_your_name\cminstaller\bundle\win32
3. from the prompt "C:\Users\enter_your_name\cminstaller\bundle\win32>" type "adb.exe sideload ClockwordMod.cer" (no quotes) and hit enter
4. This will try and sideload this .cer file and will fail - but it should kick you out to the main recovery screen. Select the Reboot option from Recovery
5. Device should boot back up. It will most likely still be the stock ROM. My guess would be that something disrupted the sideload process when installing the system.zip with CM."
However, this did not fix my problem, but it got my phone to communicate with fastboot. So I was able to flash custom recovery, and do a factory reset, which brought me to the stock ROM, I flashed CM the old-fashioned way then.....
And my PHONE IS UP AND WORKING AGAIN!!!
The main problem in communication was that phone blocked every time I booted into fastboot, and plugged USB cable in.... It immediately became unresponsive to any commands, after I did this, phone wasn't getting stuck in fastboot, so that solved my issue.

I know it's the wrong forum, but....please take a look

I really need the help of one or more of this forums intelligent minds. As I'm sure you'll see, I've posted this in the QA forum, but have had no hits so far....thus the reason for posting here.
So, about 6mos ago, my Nexus 10 stopped working and I couldn't get it back working...eventually moved onto a new tablet, which now I hate....
Anyway, I figured I'd head back to my N10 because I loved it. However, one of the reasons I left it was because it was stuck in bootloop and I was pretty sure it was bricked.
The bad news, I have followed MANY, if not ALL, of the suggestions on getting it back, I just cannot get it to boot. The good news, fastboot connects with the tablet. So, some specifics:
The tablet WILL boot into fastboot and I can send commands and the tablet is unlocked (also, I believe someone said they had issues because they had an older version of ADB and Fastboot. I'm pretty sure I downloaded the 'most current' version 1.4.3). So, with that, I was able to do the fastboot erase functions, such as cache, userdata, system, etc... and then also load the bootloader (mantafm01) and also send the stock .zip file (image-mantaray-....) and the tablet appears to load everything fine. Thumbs up, right? However, when it reboots it stops at the 'erasing' android bot and will not pass that. I left the tablet in that state for a few minutes all the way up to 3 days...no success.
I also tried the above using Wugfresh only to have the same thing occur. So, basically, I am stuck at 'erasing' and I don't know what to do. I feel confident that the tablet has the ability to be brought back to life, I just cannot figure out how/why all of the attempts lead to the same issue.
What I can also tell you is that while fastboot 'sees' the tablet, the tablet does not appear as a device in "My Computer" like it normally did when connecting via USB. I am using the original USB cable and have tried on multiple computers, all to no avail. I've downloaded/installed the drivers, as instructed on many links. Also, while I can get to the 'Recovery Mode' by pressing Power, Volume Up, Volume Down, if I choose "Recovery Mode" on the tablet, it reboots and goes to the 'erasing' screen. I have tried flashing TWRP on the tablet using fastboot as well. And, sometimes, not all the time, the TWRP blue/black screen appears but it will not progress past that screen (i.e., it doesn't go into recovery).
So, if you can, please help. I believe I have followed all of the instructions, but I have to be missing something or not following something correctly. I'm stoked that it looks like it's only soft-bricked, I just can't get it un-bricked.
Thanks in advance! I'm at my wits' end

Try fastbooting a recovery like TWRP thati s updated then flash a rom.

disclaimer: I might be no help at all!
You have fastboot -- go learn all the fastboot commands... you need to know the tools and figure a solution!
erase... hmm? why? What about factory reset? I see you are not using LOS 13 but stock image... need root? Basically, I would factory reset/wipe sdcard, then install recovery (TWRP) [okay, so first you would need to use fastboot to install custom recovery)...THEN, push (fastboot an image.zip (LOS or stock) to sdcards, install, and reboot!
Good to have WUG... another tool in the chest (I have never seen it or used it)
Ok, so one clue is that if your computer cannot see it, that says to me RED FLAG... ADB drivers? but you say fastboot works, hmm... I think this is the problem... Koush's universal ADB drivers? official Google drivers? Could these help!
Erasing screen? Hmm...
I would say, for the hell of it, try flashing different ROMs, Recoveries, and Drivers.... you are basically trying to...
Factory Reset/wipe SDcard [system, cache, ... everything], Flash custom recovery (optional), then, some how (fastboot or mycomputer) get an image on to /sdcard, then, install, then, reboot!
Good luck!
luckyheel said:
I really need the help of one or more of this forums intelligent minds. As I'm sure you'll see, I've posted this in the QA forum, but have had no hits so far....thus the reason for posting here.
So, about 6mos ago, my Nexus 10 stopped working and I couldn't get it back working...eventually moved onto a new tablet, which now I hate....
Anyway, I figured I'd head back to my N10 because I loved it. However, one of the reasons I left it was because it was stuck in bootloop and I was pretty sure it was bricked.
The bad news, I have followed MANY, if not ALL, of the suggestions on getting it back, I just cannot get it to boot. The good news, fastboot connects with the tablet. So, some specifics:
The tablet WILL boot into fastboot and I can send commands and the tablet is unlocked (also, I believe someone said they had issues because they had an older version of ADB and Fastboot. I'm pretty sure I downloaded the 'most current' version 1.4.3). So, with that, I was able to do the fastboot erase functions, such as cache, userdata, system, etc... and then also load the bootloader (mantafm01) and also send the stock .zip file (image-mantaray-....) and the tablet appears to load everything fine. Thumbs up, right? However, when it reboots it stops at the 'erasing' android bot and will not pass that. I left the tablet in that state for a few minutes all the way up to 3 days...no success.
I also tried the above using Wugfresh only to have the same thing occur. So, basically, I am stuck at 'erasing' and I don't know what to do. I feel confident that the tablet has the ability to be brought back to life, I just cannot figure out how/why all of the attempts lead to the same issue.
What I can also tell you is that while fastboot 'sees' the tablet, the tablet does not appear as a device in "My Computer" like it normally did when connecting via USB. I am using the original USB cable and have tried on multiple computers, all to no avail. I've downloaded/installed the drivers, as instructed on many links. Also, while I can get to the 'Recovery Mode' by pressing Power, Volume Up, Volume Down, if I choose "Recovery Mode" on the tablet, it reboots and goes to the 'erasing' screen. I have tried flashing TWRP on the tablet using fastboot as well. And, sometimes, not all the time, the TWRP blue/black screen appears but it will not progress past that screen (i.e., it doesn't go into recovery).
So, if you can, please help. I believe I have followed all of the instructions, but I have to be missing something or not following something correctly. I'm stoked that it looks like it's only soft-bricked, I just can't get it un-bricked.
Thanks in advance! I'm at my wits' end
Click to expand...
Click to collapse

Why not try this
I have not had this problem with my Nexus 10 but I did once with my Nexus 7 and it may help you.
Instead of trying to flash TWRP and run it (which is not working for you) why not boot into a temporary copy of TWRP and then work from that? To flash TWRP normally (persuming you had renamed the img file to TWRP which makes it easier) you would enter 'fastboot flash recovery twrp.img'. Instead of doing that type 'fastboot boot twrp.img'. This boots into TRWP and from there you will be able run all the options and from there flash TWRP and other images as normal.
If you are having problems with drivers have you used 'USBDeview' ? Run this as Administrator and delete all references to any phone or tablet USB driver and particularly look for devices with Vendor ID '18d1' or '04e8'. Just select them, right click on them and select 'Uninstall Selected Devices'. When they are all cleared reboot your computer and plug your tablet in and it should install the correct driver.
Another option I used successfully with a Nexus 7 in a boot loop was to connect it while running Linux. I don't have a Linux on a computer so I installed one in 'Oracle VM VirtualBox' I don't know Linux but after Googling for help I installed Peppermint Linux and then ADB for Linux. I downloaded the 'TWP' image into a folder in Linux and any other images I wanted. Connect your tablet to the USB port and then on the top menu in VirtualBox select 'Devices' then 'USB' and tick the option which shows your tablet. I then went into what we call a command prompt in Windows but which they call 'Terminal'. Then type 'ADB devices' and if you see it on the list use ADB instead of fastboot. As I mentioned my Nexus 7 was in a boot loop so I typed 'ADB wait-for-device' and as soon as it looped to a point where ADB could see it then the looping stopped and I could flash the images and recover the tablet.
All the best. I hope you are successful.

As long as you can get into bootloader mode, your good.
NOW
If you can't get into boot loader mode? as far as I know...
You're ****ed.
Unless you want to set up usb boot (might not work on Exynos, idk, this is magic to me) and solder the connectors and flash it like they do in factories. That's next level **** too, and considering an N10 is 100$ on amazon you're better off just grabbing a new one.

VS995 Bricked, LGUP unknown model, LG Flash Tool RX Timeout at 4%

I seem to have encountered quite the predicament. My VS995 doesn't boot any more. It shows the "Your device is corrupt. It cannot be trusted, and will not boot" message that it always has, but then it reboots and shows it again, and repeats that process forever. I cannot boot into TWRP or Fastboot mode, but Download mode still works. Upon entering download mode, the little box at the bottom says "633A B50 Modified" and the loading bar says 0%. I don't have a Windows computer (all my computers run some variant of Linux Mint) and have been using a Windows 7 VM in VirtualBox. Device manager and LG Flash Tool recognize the phone, but LG Flash Tool fails to flash it at 4% claiming an "RX Timeout" error no matter what I do with it, and the little box in the phone's download mode changes to say "633A B25 Modified." LGUP (with or without Uppercut) simply says "Unknown [COM41,]" followed by "You must select a known model, please."
I tried following this guide (https://forum.xda-developers.com/v20/how-to/guide-lg-v20-to-life-t3827732) and several others around the internet to no avail. Does anybody have any idea if this phone can be saved? Or is it destined to the dump?

Since you still get the "device is corrupt" message, you still have the engineering aboot, so you have full fastboot.
Download the KDZ for you phone and extract it. (Search, there are lots of good posts on extracting KDZs)
Boot to fastboot. With the phone off, hold vol DOWN and plug in the USB cable.
fastboot flash twrp.img recovery
fastboot reboot
Then use the key combo to try and get to TWRP. If you can't then you probably have a hardware problem (bad NAND).
Whatever you do, don't do anything that will overwrite aboot or you have a 0% chance of fixing your phone.
-- Brian

runningnak3d said:
<snip>
-- Brian
Click to expand...
Click to collapse
You boot into fastboot by holding volume down and plugging the phone into a computer, correct? Whenever I do that it just shows the "device is corrupt" screen and does the reboot loop. I can only ever get to download mode.

Try this no guaranty it will work start LG up on your computer plug in device then remove battery from device and then reboot your computer without killing LG up then put battery back in phone and restart LG up......see what happens.

Kiraisuki said:
You boot into fastboot by holding volume down and plugging the phone into a computer, correct? Whenever I do that it just shows the "device is corrupt" screen and does the reboot loop. I can only ever get to download mode.
Click to expand...
Click to collapse
When did this start? Did you do anything to your phone, or did you reboot it and it just started doing this?
-- Brian

runningnak3d said:
<snip>
-- Brian
Click to expand...
Click to collapse
For reference, I bought it used (but tested working) on eBay a month ago. First, the SD slot corrupted my SD card and then started saying the SD was not compatible with the phone. Then the SIM slot stopped reading the SIM, so I restored a backup I had made a couple days ago in TWRP and it didn't fix it. I tried dirty flashing the ROM, then clean flashing a few other ROMs, but nothing fixed either slot. After a little more of this flashing, I rebooted and the phone started doing this.

It sounds like with the flashing you did, you restored the stock aboot while you still had a modified recovery (TWRP) and modified boot (rooted) .. that is the reason you can only get to download mode -- since laf wasn't modified.
The RX timeout you are getting sounds like you have a marginal USB port or cable, you need to try flashing on another PC, and don't use VBox. I think you can still save your phone...
-- Brian

If your bootloader is unlocked then you can fix your phone, if not then i had the same problem, repaired it from market, I think he used some kind of box(maybe octopus) and got it fixed.

runningnak3d said:
<snip>
-- Brian
Click to expand...
Click to collapse
I installed Windows 7 onto a laptop and installed the programs on it. LG Flash Tool still failed at 4% claiming the KDZ and DZ didn't support something (I couldn't read it because the box was too small and it didn't scroll) but LGUP via Uppercut recognized the phone and flashed it! The phone booted to a screen with a big red 2 on it, then I reflashed it with the same KDZ in LGUP and it booted, but now it's bootlooping. I waited about 20 minutes and it didn't boot beyond the Verizon boot animation.

Kiraisuki said:
I installed Windows 7 onto a laptop and installed the programs on it. LG Flash Tool still failed at 4% claiming the KDZ and DZ didn't support something (I couldn't read it because the box was too small and it didn't scroll) but LGUP via Uppercut recognized the phone and flashed it! The phone booted to a screen with a big red 2 on it, then I reflashed it with the same KDZ in LGUP and it booted, but now it's bootlooping. I waited about 20 minutes and it didn't boot beyond the Verizon boot animation.
Click to expand...
Click to collapse
It sounds like you have a hardware problem with the NAND chip on your phone. That is the only thing that makes sense as to why you were able to get it to boot, but now it bootloops.
The data on the NAND is good enough for one boot, but then becomes corrupt....
-- Brian

runningnak3d said:
<snip>
-- Brian
Click to expand...
Click to collapse
Could the bad NAND have also caused the SIM and SD slots to stop functioning, or did the phone just basically disintegrate in my hands?

The firmware could have had problems, or whatever hardware failure messed up your NAND also toasted those.
-- Brian

runningnak3d said:
<snip>
-- Brian
Click to expand...
Click to collapse
Well that stinks. For the month I owned it, the LG V20 was the best phone I've owned so far. Oh well, thanks for helping me.

Same Boat
Kiraisuki said:
I seem to have encountered quite the predicament. My VS995 doesn't boot any more. It shows the "Your device is corrupt. It cannot be trusted, and will not boot" message that it always has, but then it reboots and shows it again, and repeats that process forever. I cannot boot into TWRP or Fastboot mode, but Download mode still works. Upon entering download mode, the little box at the bottom says "633A B50 Modified" and the loading bar says 0%. I don't have a Windows computer (all my computers run some variant of Linux Mint) and have been using a Windows 7 VM in VirtualBox. Device manager and LG Flash Tool recognize the phone, but LG Flash Tool fails to flash it at 4% claiming an "RX Timeout" error no matter what I do with it, and the little box in the phone's download mode changes to say "633A B25 Modified." LGUP (with or without Uppercut) simply says "Unknown [COM41,]" followed by "You must select a known model, please."
I tried following this guide (https://forum.xda-developers.com/v20/how-to/guide-lg-v20-to-life-t3827732) and several others around the internet to no avail. Does anybody have any idea if this phone can be saved? Or is it destined to the dump?
Click to expand...
Click to collapse
I was hoping there was a solution to Kiraisuki's post as I having similar symptoms with my phone.
My V20 is a US996 BPT with a locked boot-loader. Mine will crash apps, stop at 4% via LG Flash, then reboot into "Your device is corrupt. It cannot be trusted" then lock into the LG logo until I pull the battery 3 or 4 times forcing a restart. I also have the same results with LG Bridge.
Does the NAND chip itself fail or could the chip be reflowed to the board with a little precision work?

Stuck in rescue mode after tried flashing stock firmware

Good evening! I hope you can help me.
I flashed LineageOS 14.1, but I wanted to go back to EMUI. I made all the wipes and tried to flash different stock firmwares through a forced update (volume buttons + power button), but it never worked. At that point, I read about a guy in this forum who suggested to create a flashable zip with Huawei Update Extractor: I followed the suggestion and tried to flash it with TWRP. No error was given, but when I tried to restart, TWRP told me I had no OS installed. I thought it was strange, so I tried to restart anyway. That's when I got in rescue mode. I can't get into the recovery and I can't use fastboot. What rescue mode shows me is:
RESCUE MODE
Attention!
Please update system again
Update User Guide:
*link*
*android avatar*
Error!
Func NO: 10 (boot image)
Error NO: 2 (load failed!)
Pressing the three buttons, I'm able to force an update. The problem is I can't find a firmware that doesn't get rejected. With Lollipop firmwares, it starts to install, but it fails at 12%. With Marshmallow ones, the installation process doesn't even start.
What can I do to make it work again? I'm very sad because this phone was gifted to me a couple of days ago and I already messed it up. I don't even know how to turn it off.
What can I do to get in fastboot mode? At that point, what should I do to flash the stock firmware? Or maybe do I need to find the first stock firmware ever installed into this phone to make the forced update work?
Please, I need help. Thank you in advance!
P.S. The phone's model is ALE-L21. I live in Italy, so I assume it's a European version.

Did you managed to fix this?

Jhon_Locke said:
Did you managed to fix this?
Click to expand...
Click to collapse
Not yet, but I'm working on it. I found out that the device is recognized by my PC if I follow these steps:
1. Connect the phone to the PC and wait for it to go in rescue mode;
2. Wait until the notification LED stops to blink;
3. Disconnect the USB cable;
4. Press volume - and power button;
5. Reconnect the cable.
At that point, the screen turns black and the phone is recognized as "㄰㌲㔴㜶㤸". I installed the drivers and now it's recognized as "HUAWEI USB COM 1.0". I should be able to reflash the partitions and make my phone work again, but I'm still trying to understand how to do it correctly.
Any help is appreciated!

ErikChimello said:
Not yet, but I'm working on it. I found out that the device is recognized by my PC if I follow these steps:
1. Connect the phone to the PC and wait for it to go in rescue mode;
2. Wait until the notification LED stops to blink;
3. Disconnect the USB cable;
4. Press volume - and power button;
5. Reconnect the cable.
At that point, the screen turns black and the phone is recognized as "㄰㌲㔴㜶㤸". I installed the drivers and now it's recognized as "HUAWEI USB COM 1.0". I should be able to reflash the partitions and make my phone work again, but I'm still trying to understand how to do it correctly.
Any help is appreciated!
Click to expand...
Click to collapse
fastboot detects your device when you plug it into your computer?
I mean, if you run "fastboot devices" it shows your phone?
I've had this same problem but with an P8 Lite 2017, after flashing some ROM that supposedly was the stock one and trying to flash recovery I ended up with my phone bootlooping into rescue mode, I was able to "bypass" this thing rebooting my phone like crazy, seriously like after 20 reboot it finally booted into the damn ROM and I never touched the phone again. Sometimes when the phone ran out of battery and tried to power it on the phone booted into rescue mode and again after some reboots it booted to Android but now I want to install a custom ROM or at the very least root this damn phone so that's why I'm asking you if you have solved this, if you do then probably if I follow the same steps I would be able to fix that screen, hopefully.
If you are able to flash something start with flashing all recoveries your update.app has, maybe that's the problem (at least in my phone it is).

Jhon_Locke said:
fastboot detects your device when you plug it into your computer?
I mean, if you run "fastboot devices" it shows your phone?
I've had this same problem but with an P8 Lite 2017, after flashing some ROM that supposedly was the stock one and trying to flash recovery I ended up with my phone bootlooping into rescue mode, I was able to "bypass" this thing rebooting my phone like crazy, seriously like after 20 reboot it finally booted into the damn ROM and I never touched the phone again. Sometimes when the phone ran out of battery and tried to power it on the phone booted into rescue mode and again after some reboots it booted to Android but now I want to install a custom ROM or at the very least root this damn phone so that's why I'm asking you if you have solved this, if you do then probably if I follow the same steps I would be able to fix that screen, hopefully.
If you are able to flash something start with flashing all recoveries your update.app has, maybe that's the problem (at least in my phone it is).
Click to expand...
Click to collapse
No, it doesn't show anything if I write that command...
I guess mine won't ever boot into the rom because it seems like there's no system installed. I made some researches and found out there are some softwares that let you reflash the partitions IF the phone is recognized as "HUAWEI USB COM 1.0". I'm still trying to figure out how to do it correctly though. I feel like if I do something wrong, then my phone won't probably turn on again.
In your case, you should be able to flash a custom rom without any issue. You just have to be very careful and inform you as much as you can: I don't want your phone to end up like mine?. Anyway, it seems pretty hard to go back to the stock rom, so think about it before you flash a custom rom. Also, make a Nandroid Backup is very important.