Database Users

[Q] Updating to 4.2.2 , I'm going crazy !

Hi everybody !
I'm very sorry to post, i know a lot of people have the same problem as me, I have seen a lot of post but every time the only answer of member is : go see the huge 4.2.2 post !
Since yesterday morning I'm trying to update my nexus 7 4.2.1 to 4.2.2.
I know the problem, I have installed stickmount that have problably changed some system files and now every time i want update by anyway I have an error 7 saying that asset check doesnt match etc etc.... apparently a file system/lib/debbugr something like that.
I've wipe all the data, i did a factory reset, always the same problem.
With CWM 6 or TWR I have tried to update with the OTA zip 4.2.2 , with the 4.2.1 too .... Error error error... Even if i uncheck the verification !!!!
I have downloaded this factory image too : nakasi-jdq39-factory-c317339e.tgz
Trying to install it with WugFresh toolkit.... Installation aborded after the check... I had an S1 S2 , i ve unlocked my Nexus 7 , root it etc... But for the first time I'm totally blocked !!!!
Please... I beg you... Help me, I know you will send me probably to an other post but please not a generic one, I'm really turning mad.
Thank you for your help, I'm ready to answer to any question, and to try everything. I have all the tools installed on my computer... Thank you by advance

Here is the full error message :
assert failed: apply_patch_check ("system/bin/debuggerd", "xxxxxxxxxxx"
E:Error in /sdcard/readytoflash/signed-nakasi-jdq39-from-JOP40D
statut 7 etc....

Just tried something and maybe it's gonna work.... fingers crossed....
I download the full factory image of the 4.2.2
launch my nexus 7 in bootloader and after i have exec those commands :
fastboot oem unlock
fastboot erase boot
fastboot erase cache
fastboot erase recovery
fastboot erase system
fastboot erase userdata
fastboot flash bootloader bootloader-grouper-4.18.img
fastboot reboot-bootloader
fastboot -w update image-nakasi-jdq39.zip

Command Prompt for manual input...
------------------------------------------------------------------
Try typing "adb help" or "fastboot help" for a full cmd list and syntax info.
Enjoy...
C:\WugFresh Development\data>fastboot oem
C:\WugFresh Development\data>unlockfastboot
'unlockfastboot' is not recognized as an internal or external command,
operable program or batch file.
C:\WugFresh Development\data>fastboot help
usage: fastboot [ <option> ] <command>
commands:
update <filename> reflash device from update.zip
flashall flash boot + recovery + system
flash <partition> [ <filename> ] write a file to a flash partition
erase <partition> erase a flash partition
format <partition> format a flash partition
getvar <variable> display a bootloader variable
boot <kernel> [ <ramdisk> ] download and boot kernel
flash:raw boot <kernel> [ <ramdisk> ] create bootimage and flash it
devices list all connected devices
continue continue with autoboot
reboot reboot device normally
reboot-bootloader reboot device into bootloader
help show this help message
options:
-w erase userdata and cache (and format
if supported by partition type)
-u do not first erase partition before
formatting
-s <specific device> specify device serial number
or path to device port
-l with "devices", lists device paths
-p <product> specify product name
-c <cmdline> override kernel commandline
-i <vendor id> specify a custom USB vendor id
-b <base_addr> specify a custom kernel base address
-n <page size> specify the nand page size. default:
2048
-S <size>[K|M|G] automatically sparse files greater th
an
size. 0 to disable
C:\WugFresh Development\data>fastboot devices
015d2d431d641e0b fastboot
C:\WugFresh Development\data>fastboot oem unlockfastboot
...
(bootloader) Bootloader is already unlocked
OKAY [ 0.020s]
finished. total time: 0.021s
C:\WugFresh Development\data>erase
The syntax of the command is incorrect.
C:\WugFresh Development\data>erase bootfastboot
Could Not Find C:\WugFresh Development\data\bootfastboot
C:\WugFresh Development\data>fastboot erase
usage: fastboot [ <option> ] <command>
commands:
update <filename> reflash device from update.zip
flashall flash boot + recovery + system
flash <partition> [ <filename> ] write a file to a flash partition
erase <partition> erase a flash partition
format <partition> format a flash partition
getvar <variable> display a bootloader variable
boot <kernel> [ <ramdisk> ] download and boot kernel
flash:raw boot <kernel> [ <ramdisk> ] create bootimage and flash it
devices list all connected devices
continue continue with autoboot
reboot reboot device normally
reboot-bootloader reboot device into bootloader
help show this help message
options:
-w erase userdata and cache (and format
if supported by partition type)
-u do not first erase partition before
formatting
-s <specific device> specify device serial number
or path to device port
-l with "devices", lists device paths
-p <product> specify product name
-c <cmdline> override kernel commandline
-i <vendor id> specify a custom USB vendor id
-b <base_addr> specify a custom kernel base address
-n <page size> specify the nand page size. default:
2048
-S <size>[K|M|G] automatically sparse files greater th
an
size. 0 to disable
C:\WugFresh Development\data>fastboot erase bootfastboot
erasing 'bootfastboot'...
FAILED (remote: Invalid Partition Name.)
finished. total time: 0.025s
C:\WugFresh Development\data>fastboot erase boot
erasing 'boot'...
OKAY [ 0.139s]
finished. total time: 0.140s
C:\WugFresh Development\data>fastboot erase cache
******** Did you mean to fastboot format this partition?
erasing 'cache'...
OKAY [ 0.285s]
finished. total time: 0.287s
C:\WugFresh Development\data>fastboot erase recovery
erasing 'recovery'...
OKAY [ 0.139s]
finished. total time: 0.140s
C:\WugFresh Development\data>fastboot erase system
******** Did you mean to fastboot format this partition?
erasing 'system'...
OKAY [ 0.534s]
finished. total time: 0.535s
C:\WugFresh Development\data>fastboot erase userdata
******** Did you mean to fastboot format this partition?
erasing 'userdata'...
OKAY [ 17.099s]
finished. total time: 17.100s
C:\WugFresh Development\data>fastboot flash bootloader bootloader-grouper-4.18.i
mg
sending 'bootloader' (2096 KB)...
OKAY [ 0.287s]
writing 'bootloader'...
OKAY [ 1.960s]
finished. total time: 2.250s
C:\WugFresh Development\data>fastboot reboot-bootloader
rebooting into bootloader...
OKAY [ 0.020s]
finished. total time: 0.022s
C:\WugFresh Development\data>fastboot -w update image-nakasi-jdq39.zip
archive does not contain 'boot.sig'
archive does not contain 'recovery.sig'
archive does not contain 'system.sig'
--------------------------------------------
Bootloader Version...: 4.18
Baseband Version.....: N/A
Serial Number........: 015d2d431d641e0b
--------------------------------------------
checking product...
OKAY [ 0.040s]
checking version-bootloader...
OKAY [ 0.022s]
sending 'boot' (4944 KB)...
OKAY [ 0.645s]
writing 'boot'...
OKAY [ 1.877s]
sending 'recovery' (5446 KB)...
OKAY [ 0.702s]
writing 'recovery'...
OKAY [ 0.224s]
erasing 'system'...
OKAY [ 0.112s]
sending 'system' (471804 KB)...
OKAY [ 59.948s]
writing 'system'...
OKAY [ 29.385s]
erasing 'userdata'...
OKAY [ 4.919s]
formatting 'userdata' partition...
Creating filesystem with parameters:
Size: 30080499712
Block size: 4096
Blocks per group: 32768
Inodes per group: 8160
Inode size: 256
Journal blocks: 32768
Label:
Blocks: 7343872
Block groups: 225
Reserved block group size: 1024
Created filesystem with 11/1836000 inodes and 159268/7343872 blocks
sending 'userdata' (139157 KB)...
writing 'userdata'...
OKAY [ 33.302s]
erasing 'cache'...
OKAY [ 0.077s]
formatting 'cache' partition...
Creating filesystem with parameters:
Size: 464519168
Block size: 4096
Blocks per group: 32768
Inodes per group: 7088
Inode size: 256
Journal blocks: 1772
Label:
Blocks: 113408
Block groups: 4
Reserved block group size: 31
Created filesystem with 11/28352 inodes and 3654/113408 blocks
sending 'cache' (9052 KB)...
writing 'cache'...
OKAY [ 1.847s]
rebooting...
finished. total time: 133.304s
Click to expand...
Click to collapse
So....It look likes to work... Speaking alone helped me a lot.. I leave the post here for those who have the same issue.

wiseman-fr said:
So....It look likes to work... Speaking alone helped me a lot.. I leave the post here for those who have the same issue.
Click to expand...
Click to collapse
Heheh, so it seems your imaginary friend helped you out :sly:
Sent from my Nexus 7 using Tapatalk HD

N7 stick on bootloader, no cache, cant unlock

Hi.
I have in the past had to come crying on here for you miracle workers to help me so im here again
The nexus 7 unit was running well. I had a few issues with random shut downs and was getting concerned.
what i ultimately wish for is a back to stock factory fresh install nexus 7
after searches found a reset may help
got into bootloader
into recovery and tried a factory reset
the unit stopped at wiping /data
a press of buttons changed this to the android dude with a swirling tummy. Left this to no joy
Started again. this time cleared cache. This had the same error. (just sat there)
Then i got an error indicated the E:failed to mount /cache (invalid argument)
basically E: cant be accessed
So, i decided to look a bit further and unlocking the unit seemed to be the only way i was going to fix this....
problem is it wont let me unlock my bootloader
i get
C:\google>fastboot oem unlock
...
(bootloader) erasing userdata...
(bootloader) erasing userdata done
(bootloader) erasing cache...
(bootloader) erasing cache done
(bootloader) unlocking...
FAILED (remote: (Unknown error code))
finished. total time: 1.614s
the unit is still locked
i now have a nexus 7 that will boot into bootloader, recovery
so i can adb sideload, i can get to fastboot
i have tried flash from fastboot etc
i pray someone can help
i have tried formatting the cache to rebuild???
here is what i got
C:\google>fastboot erase cache
erasing 'cache'...
OKAY [ 3.071s]
finished. total time: 3.076s
C:\google>fastboot format cache
formatting 'cache' partition...
Creating filesystem with parameters:
Size: 464519168
Block size: 4096
Blocks per group: 32768
Inodes per group: 7088
Inode size: 256
Journal blocks: 1772
Label:
Blocks: 113408
Block groups: 4
Reserved block group size: 31
Created filesystem with 11/28352 inodes and 3654/113408 blocks
sending 'cache' (9052 KB)...
FAILED (remote: Bootloader is locked.)
finished. total time: 0.304s

I am concerned that there is no answer...
I am having the same issue.

I think your device's nand chip got corrupted. You can't do much about it. Try to send it to Google/Asus.

I hope that's not the case...

cant unlock bootloader, tried every method I can find

Command Prompt for manual input...
------------------------------------------------------------------
Try typing "adb help" or "fastboot help" for a full cmd list and syntax info.
Enjoy...
C:\Program Files (x86)\WugFresh Development\Nexus Root Toolkit\data>fastboot oem
unlock
...
(bootloader) erasing userdata...
(bootloader) erasing userdata done
(bootloader) erasing cache...
(bootloader) erasing cache done
(bootloader) unlocking...
FAILED (remote: ()
finished. total time: 5.157s
C:\Program Files (x86)\WugFresh Development\Nexus Root Toolkit\data>fastboot oem
unlock
...
(bootloader) erasing userdata...
(bootloader) erasing userdata done
(bootloader) erasing cache...
(bootloader) erasing cache done
(bootloader) unlocking...
FAILED (remote: ()
finished. total time: 7.991s
C:\Program Files (x86)\WugFresh Development\Nexus Root Toolkit\data>fastboot -w
Creating filesystem with parameters:
Size: 14442037248
Block size: 4096
Blocks per group: 32768
Inodes per group: 8176
Inode size: 256
Journal blocks: 32768
Label:
Blocks: 3525888
Block groups: 108
Reserved block group size: 863
Created filesystem with 11/883008 inodes and 96825/3525888 blocks
Creating filesystem with parameters:
Size: 464519168
Block size: 4096
Blocks per group: 32768
Inodes per group: 7088
Inode size: 256
Journal blocks: 1772
Label:
Blocks: 113408
Block groups: 4
Reserved block group size: 31
Created filesystem with 11/28352 inodes and 3654/113408 blocks
erasing 'userdata'...
OKAY [ 0.020s]
sending 'userdata' (137526 KB)...
FAILED (remote: Bootloader is locked.)
finished. total time: 0.041s
C:\Program Files (x86)\WugFresh Development\Nexus Root Toolkit\data>
Click to expand...
Click to collapse
My nexus7 is stuck in a 'groundhog day' scenario, no matter what I do after reboot it reverts to it's former state, factory reset has no effect and I cant unlock to reflash, any advice? thanks

Everything I've read on this suggests a bad emmc chip or something along that lines.
I do suggest you try different drivers, perhaps from this thread...
http://forum.xda-developers.com/showthread.php?t=1907796
But if it won't unlock , you're dead in the water as far as Modifying goes.
I would return it and get another personally. ?

Darth said:
Everything I've read on this suggests a bad emmc chip or something along that lines.
Click to expand...
Click to collapse
thanks for replying, pretty sure that was the case
Darth said:
I do suggest you try different drivers, perhaps from this thread...
http://forum.xda-developers.com/showthread.php?t=1907796
But if it won't unlock , you're dead in the water as far as Modifying goes.
I would return it and get another personally.
Click to expand...
Click to collapse
been like this since the 4.3 ota update, asked around at the time, nobody had a clue, seems to be a common fault now, Google were not interested... might try Asus

Nexus 4 OTA soft-brick help

I was updating my Mom's Nexus 4 to 4.4 (with the intention of bringing it to the current version to address various security issues -- like stagefright), but it appears to have "soft-bricked" as some people are calling it.
- locked bootloader
- not rooted.
- stock firmware
It goes into a "bootloop"? Where the Google logo displays forever (at least 30 minutes) w/o doing anything.
Normally I'd have spent more time doing this (e.g. backing it up, etc). But due to various personal mishaps in the past year, my tech environment is incomplete and a mess. I've never had problems w/ OTA updates so I foolishly went ahead w/o an adb backup -- which would have at least given me most files (even if I have to redo the entire setup). Also, due to poor timing, I was in a rush to get this done so she'd have a week or so before her trip to get used to the small changes (yes, she freaks out over small changes like the camera UI being different). So, whenever you're doing 2 things at once, you never pay attention to one thing fully. And this is also what happened to the OTA update -- so if there were ANY error messages or anything during the update, I did not notice. =(
Unfortunately I also don't have the device in front of me (things like work get in the way of personal masochism -- aka playing with tech).
Anyhow... I'm not exactly certain if it was going to 4.4. When I downloaded the OTA images for the Nexus 4 for 4.4 and tried to flash using the flash-all tool, it complained that the bootloader was not the right one. When I pulled down 4.3 and tried to flash, it did not complain about that bootloader version. So perhaps it didn't properly flash the bootloader? In any case, is there any chance of getting at the files now before a wipe?
What confuses me, is why I cannot flash w/ a STOCK image. Aren't they signed? Even with a locked bootloader, couldn't it in theory let the right images in?
Also, I'm normally in a windows environment, but due to my machines all being down, I'm on the work MacBook Pro instead. So unfortunately I can't try WugFresh's rootkit -- although I'm not sure it would help w/ a locked boot loader.
So... the questions are:
1) Is there a way to flash to a stock OTA image w/o losing data?
2) Or if that's not possible, is it possible to get the data from the phone?
3) Or I'm out of luck and I shouldn't waste any more time trying to recover what's lost?
(Btw, I didn't lose everything -- e.g. I have photos, sms and call logs backed up. WhatsApp used to be backed up, but it seems like both the 3rd party solution and WhatsApp themselves have stopped supporting some sort of offline backup. So mainly just concerned about files in Downloads or Documents or something -- everything else I've made sure was "on the cloud".)

First you might try going into Recovery (assuming you can) and wipe the cache partition, then reboot and see if that fixes it. I have had this glitch occur during an OTA update before (It might have been the 4.4 update actually), and wiping the cache and rebooting fixed it every time.
I am trying to understand what happened and what you did exactly. You have a locked bootloader, aren't rooted, and on stock. You are saying OTA and that you tried to flash via flash-all. Are you using the term OTA and referring to the image files in the tarball as the same thing? OTA is the zip file which only contains the files necessary to go from one version to the next higher version. The .tgz factory image file has all of the image files for a complete build. You would not have been able to flash them with a locked bootloader however. Is that what happened here? You tried to flash the img files on a locked bootloader?
Are you able to boot into Fastboot? (Power off your Nexus 4, and reboot it into fastboot mode by holding the volume down button and power.) If so, will your computer recognize your device? You should install Minimal ADB and Fastboot: http://lifehacker.com/the-easiest-way-to-install-androids-adb-and-fastboot-to-1586992378 on your Mac and see if it will recognize your device.
If you can get it recognized in Fastboot, you can then just use the fastboot oem unlock command in a terminal window. If you can get the bootloader unlocked, you can then flash the image files properly to recover the device. Here are some instructions: http://www.androidcentral.com/how-unlock-nexus-4-bootloader (***This will wipe your device and you will lose your data if you have to go this route***)

The first thing I did was to try wiping the cache after recovery mode, but that did not take it out of the boot loop. AFAIK, in 4.3 you can't wipe the dalvik cache from stock recovery. Something similar also happened to me on my Nexus 4 a while back and yes, wiping the cache then did the trick (also think it was 4.4). It fixed it then on my Nexus 4, but not on the current one.
The initial flash was applied OTA. (e.g. There's been an "upgrade" icon in the notifications bar for like over a year.) So you touch the notification, it tells you to reboot and install and I let it w/o paying much attention to it afterwards until I noticed that it only displayed a Google logo afterwards (for over 30 minutes). If that flash takes longer than that, I could have screwed up and interrupted it. :crying: I can't recall how long the 4.4 takes to flash.
Since it was in a boot loop, I thought I could reflash from the tgz images from here: https://developers.google.com/android/nexus/images?hl=en, but of course w/ a locked boot loader, nothing will flash.
Looking at this thread, there seems to be a "manual" way to unlock the boot loader w/o wiping the device IF the Nexus 4 was on a version younger than 4.3.
http://forum.xda-developers.com/nex...ot-unlock-bootloader-wipe-data-t2300480/page4 - comment 35 for "steps", somewhere else for confirmation that it's not working for 4.3 and later.
So, it seems like there is no way to reflash this phone w/ anything w/o wiping the data (4.3 and after) -- which was what this question was about.
So maybe this bears repeating (to be clear). The question is:
Is there a way to recover from a boot loop caused by an OTA update from 4.3 to 4.4 when it is a stock and unrooted rom, with a stock (locked) boot loader without losing data?
-or- Is there a way to recover the data in such a state?
Of course there seems to be a way to JTAG it, but... that scares me (since I've never done that kind of stuff): http://forensicswiki.org/wiki/JTAG_LG_E960_(Nexus_4)
But I do have another question, if I accidentally interrupted the flash, is it possible to get it going again?
This might be insightful (but probably not).
--------
Code:
mbpro:occam-krt16s tofumaster$ ./flash-all.sh
sending 'bootloader' (2203 KB)...
OKAY [ 0.072s]
writing 'bootloader'...
FAILED (remote: not supported in locked device)
finished. total time: 0.073s
rebooting into bootloader...
OKAY [ 0.001s]
finished. total time: 0.001s
sending 'radio' (45537 KB)...
OKAY [ 1.437s]
writing 'radio'...
FAILED (remote: not supported in locked device)
finished. total time: 1.438s
rebooting into bootloader...
OKAY [ 0.001s]
finished. total time: 0.001s
archive does not contain 'boot.sig'
archive does not contain 'recovery.sig'
archive does not contain 'system.sig'
archive does not contain 'vendor.img'
Creating filesystem with parameters:
Size: 6189744128
Block size: 4096
Blocks per group: 32768
Inodes per group: 8048
Inode size: 256
Journal blocks: 23612
Label:
Blocks: 1511168
Block groups: 47
Reserved block group size: 375
Created filesystem with 11/378256 inodes and 50366/1511168 blocks
Creating filesystem with parameters:
Size: 587202560
Block size: 4096
Blocks per group: 32768
Inodes per group: 7168
Inode size: 256
Journal blocks: 2240
Label:
Blocks: 143360
Block groups: 5
Reserved block group size: 39
Created filesystem with 11/35840 inodes and 4616/143360 blocks
--------------------------------------------
Bootloader Version...: MAKOZ20i
Baseband Version.....: M9615A-CEFWMAZM-2.0.1700.84
Serial Number........: 0xxxxxxxxxxxxxxb
--------------------------------------------
checking product...
OKAY [ 0.002s]
checking version-bootloader...
FAILED
Device version-bootloader is 'MAKOZ20i'.
Update requires 'MAKOZ30d'.
finished. total time: 0.010s
Code:
mbpro:occam-krt16s tofumaster$ cd ..
mbpro:Nexus4 tofumaster$ ls
occam-jwr66y-factory-74b1deab_(v4.3).tgz occam-krt16s-factory-2006f418_(v4.4).md5
occam-krt16s occam-krt16s-factory-2006f418_(v4.4).tgz
mbpro:Nexus4 tofumaster$ md5 occam-jwr66y-factory-74b1deab_\(v4.3\).tgz > occam-jwr66y-factory-74b1deab_\(v4.3\).md5
mbpro:Nexus4 tofumaster$ ls
occam-jwr66y-factory-74b1deab_(v4.3).md5 occam-krt16s-factory-2006f418_(v4.4).md5
occam-jwr66y-factory-74b1deab_(v4.3).tgz occam-krt16s-factory-2006f418_(v4.4).tgz
occam-krt16s
mbpro:Nexus4 tofumaster$ cat *.md5
MD5 (occam-jwr66y-factory-74b1deab_(v4.3).tgz) = 6f6db7729bc6b8089683bc5297a09b93
MD5 (occam-krt16s-factory-2006f418_(v4.4).tgz) = e60c3077c9bc9bd106eb3077992f0d6c
mbpro:Nexus4 tofumaster$ tar xvzf occam-jwr66y-factory-74b1deab_\(v4.3\).tgz
x occam-jwr66y/
x occam-jwr66y/radio-mako-m9615a-cefwmazm-2.0.1700.84.img
x occam-jwr66y/flash-base.sh
x occam-jwr66y/bootloader-mako-makoz20i.img
x occam-jwr66y/flash-all.bat
x occam-jwr66y/image-occam-jwr66y.zip
x occam-jwr66y/flash-all.sh
Code:
mbpro:Nexus4 tofumaster$ cd occam-jwr66y
mbpro:occam-jwr66y tofumaster$ ls
bootloader-mako-makoz20i.img flash-base.sh
flash-all.bat image-occam-jwr66y.zip
flash-all.sh radio-mako-m9615a-cefwmazm-2.0.1700.84.img
mbpro:occam-jwr66y tofumaster$ ./flash-all.sh
sending 'bootloader' (2201 KB)...
OKAY [ 0.072s]
writing 'bootloader'...
FAILED (remote: not supported in locked device)
finished. total time: 0.073s
rebooting into bootloader...
OKAY [ 0.001s]
finished. total time: 0.001s
sending 'radio' (54321 KB)...
OKAY [ 1.712s]
writing 'radio'...
FAILED (remote: not supported in locked device)
finished. total time: 1.713s
rebooting into bootloader...
OKAY [ 0.001s]
finished. total time: 0.001s
archive does not contain 'boot.sig'
archive does not contain 'recovery.sig'
archive does not contain 'system.sig'
archive does not contain 'vendor.img'
Creating filesystem with parameters:
Size: 6189744128
Block size: 4096
Blocks per group: 32768
Inodes per group: 8048
Inode size: 256
Journal blocks: 23612
Label:
Blocks: 1511168
Block groups: 47
Reserved block group size: 375
Created filesystem with 11/378256 inodes and 50366/1511168 blocks
Creating filesystem with parameters:
Size: 587202560
Block size: 4096
Blocks per group: 32768
Inodes per group: 7168
Inode size: 256
Journal blocks: 2240
Label:
Blocks: 143360
Block groups: 5
Reserved block group size: 39
Created filesystem with 11/35840 inodes and 4616/143360 blocks
--------------------------------------------
Bootloader Version...: MAKOZ20i
Baseband Version.....: M9615A-CEFWMAZM-2.0.1700.84
Serial Number........: 0xxxxxxxxxxxxxxb
--------------------------------------------
checking product...
OKAY [ 0.002s]
checking version-bootloader...
OKAY [ 0.002s]
checking version-baseband...
OKAY [ 0.002s]
sending 'boot' (6194 KB)...
OKAY [ 0.200s]
writing 'boot'...
FAILED (remote: not supported in locked device)
finished. total time: 0.213s
mbpro:occam-jwr66y tofumaster$ fastboot devices
0xxxxxxxxxxxxxxb fastboot

A solution!
Okay, just to update anyone following this thread.
I sideloaded this: http: // www . androidpolice . com /2013/11/21/the-nexus-4-finally-gets-4-4-heres-how-you-can-flash-the-kitkat-krt16s-ota-manually-root-or-unlock-not-required/
And it worked. But I haven't slept in over 24 hours, so... I think I'm going to sleep now (have to be up in another 4...). Will post more details later (or answer any questions).

More details
Okay, not much to add, but sometimes these details can be helpful in the future for other people.
When I first posted this, I was past the point of diminishing returns (e.g. where anything you do creates more problems than fixes them). So I was thinking down the wrong path.
ariesgodofwar pointed out that I was trying to apply a the Factory Image over the phone which was NOT the OTA image (which contains only the things it needs to do an update). This clued me in. The OTA update is always a patch. And I'm glad the factory images did not apply because inside the .tgz is a userdata.img which would have wiped all my data anyhow. So... lucky that did not happen.
Instead, I found a signed OTA update (at Android Police) and then used the adb "sideload" technique to apply it. Fortunately, it looked like either nothing was patched successfully the first time, or it happily skipped fully patched files (e.g. maybe it was a mix between 4.3 and 4.4 which was why it was stuck in a boot-loop) and never told me about it on the logs.
Anyhow, it seems to have patched okay, and then went back to the Recovery Menu where I did another Cache Partition Wipe just in case before rebooting. After that, it went to optimizing apps and everything worked as expected. :victory:
In the link above, there's another link that shows you exactly how to get it into the Recover Menu but here it is anyhow: http: // www . androidpolice . com /2012/11/13/android-4-2-build-jop40c-rolling-out-to-the-nexus-7-now-manual-download-link-available/
(btw, how on earth did I post links in the 2nd post???)

Nexus 7 2012 Wi-Fi stucked at bootloader

Hi all, I'm really a newbie and hope you can help me with my Nexus 7 2012 wi-fi.
I tried to downgrade to 4.4.4 ( becasuse from 5.0 the tablet was unusable) following the instructions I found on gottabemobile.
I unlocked the device and everything seemed ok but when I try to write the new image with flash-all.bat I get the following errors, like the computer can't communicate with the device.
Code:
...
OKAY [ 0.000s]
finished. total time: 0.000s
erasing 'boot'...
FAILED (remote: (Timeout))
finished. total time: 2.044s
erasing 'cache'...
FAILED (remote: (Timeout))
finished. total time: 2.028s
erasing 'recovery'...
FAILED (remote: (Timeout))
finished. total time: 2.028s
erasing 'system'...
FAILED (remote: (Timeout))
finished. total time: 2.028s
erasing 'userdata'...
FAILED (remote: (Timeout))
finished. total time: 2.028s
sending 'bootloader' (2100 KB)...
FAILED (remote: (Timeout))
finished. total time: 2.028s
rebooting into bootloader...
FAILED (remote: (Nv3pBadReceiveLength))
finished. total time: 1.014s
archive does not contain 'boot.sig'
archive does not contain 'recovery.sig'
archive does not contain 'system.sig'
archive does not contain 'vendor.img'
Creating filesystem with parameters:
Size: 14569963520
Block size: 4096
Blocks per group: 32768
Inodes per group: 8160
Inode size: 256
Journal blocks: 32768
Label:
Blocks: 3557120
Block groups: 109
Reserved block group size: 871
Created filesystem with 11/889440 inodes and 97309/3557120 blocks
Creating filesystem with parameters:
Size: 464519168
Block size: 4096
Blocks per group: 32768
Inodes per group: 7088
Inode size: 256
Journal blocks: 1772
Label:
Blocks: 113408
Block groups: 4
Reserved block group size: 31
Created filesystem with 11/28352 inodes and 3654/113408 blocks
--------------------------------------------
Bootloader Version...: 4.23
Baseband Version.....: N/A
Serial Number........: 015d2856b1400802
--------------------------------------------
checking product...
OKAY [ 0.031s]
checking version-bootloader...
OKAY [ 0.016s]
sending 'boot' (4994 KB)...
FAILED (data transfer failure (Unknown error))
finished. total time: 5.179s
If I try a fastboot devices I can see the serial number of the tablet but it is stucked in fastboot mode.
The bootloader is v. 4.23, product name is grouper, the image I'm using is image-nakasi-ktu84p (nakasi-ktu84p-factory-2c6e4d6f.tgz)
In computer management I see Android Device > Android Bootloader Interface
What did I do wrong? Have I bricked the device or it can be saved? Thanks in advance for any help.

Did you try with a different USB cable / a different USB port? Because it looks really as a communication problem.
Nevertheless be sure not to flash one of the factory images which contain a defective bootloader! Normally I am unpacking the factory image and flash boot.img and system.img manually by fastboot, i.e.:
- fastboot flash boot boot.img
- fastboot flash system system.img

Thanks for your help AndDiSa: I changed cable and port and flashed the images one by one and it worked!
Just one question: is Android 4.3 faster that 4.4 on the Nexus 7? Will I miss something big if I downgrade to 4.3?

You should probably even try 6.x