nexus 6p doesn't boot, with error when trying to unlock - Nexus 6P Q&A, Help & Troubleshooting

Greeting,
My nexus 6P, suddenly while having a phone call, got freeze, then rebooted,
Then it keeps rebooting, showing Google “in white” while booting, then off, restart again “by itself”, and same in loop
Started the device into fastboot mode, selected recovery mode
Again same issue, restart, shows Google “in white” then restart again
Tried to follow the instructions, at [GUIDE] Unlock/Root/Flash for Nexus 6P
https://forum.xda-developers.com/nexus-6p/general/guides-how-to-guides-beginners-t3206928
Commands and results are here
C:\nexus6p\angler-n4f26o>adb version
Android Debug Bridge version 1.0.36
Revision 0e9850346394-android
C:\nexus6p\angler-n4f26o>adb devices
List of devices attached
<Notice no result returned>
C:\nexus6p\angler-n4f26o>fastboot devices
8XV7N16126000082 fastboot
Please note, I checked those points
ADB and fastboot, downloaded from the link provided in the guide, as well I downloaded it from Google directly
USB driver, updated with latest from google
Java, updated
And of course, I cannot run the device, to do any required configuration on it
And here is a copy of the device details

malibusa said:
Greeting,
My nexus 6P, suddenly while having a phone call, got freeze, then rebooted,
Then it keeps rebooting, showing Google “in white” while booting, then off, restart again “by itself”, and same in loop
Started the device into fastboot mode, selected recovery mode
Again same issue, restart, shows Google “in white” then restart again
Tried to follow the instructions, at [GUIDE] Unlock/Root/Flash for Nexus 6P
https://forum.xda-developers.com/nexus-6p/general/guides-how-to-guides-beginners-t3206928
Commands and results are here
C:\nexus6p\angler-n4f26o>adb version
Android Debug Bridge version 1.0.36
Revision 0e9850346394-android
C:\nexus6p\angler-n4f26o>adb devices
List of devices attached
<Notice no result returned>
C:\nexus6p\angler-n4f26o>fastboot devices
8XV7N16126000082 fastboot
Please note, I checked those points
ADB and fastboot, downloaded from the link provided in the guide, as well I downloaded it from Google directly
USB driver, updated with latest from google
Java, updated
And of course, I cannot run the device, to do any required configuration on it
And here is a copy of the device details
Click to expand...
Click to collapse
If you can get into bootloader mode then maybe try fastest flashing things like stock recovery. If you manage to get stock recovery then boot into it and adb sideload a stock OTA from Google Developer website. Other than that I'm not too sure, you might need to contact Google/Huawei if that or anything else doesn't work.
---------- Post added at 08:43 PM ---------- Previous post was at 08:35 PM ----------
Okay, in bootloader mode try flashing the stock bootloader image from their OTA by typing fastboot flash bootloader (drag bootloader image here) then type fastboot reboot-bootloader. After that type fastboot flash radio (drag radio image here). Then type fastboot reboot-bootloader again. After that you can try booting up. If you are somehow able to get into recovery mode whether you can boot up normally or not then you can simply adb sideloading the stock OTA. If nothing I have said gets you into recovery or to boot up the device then you are probably screwed to be honest. Good luck

Hi,
thanks for your reply,
let me make sure, that i understood you clearly,
when i boot into bootloader, and select the recovery mode,
it get rebooted, shows Google “in white” then restart again, and again in same loop exactly as if i booted normally, not into the bootloader
as i read in other posts, i should expect the device to show me a confirmation message, or something similar,
but in my case, nothing at all, restart, and keep restarting
The options i have with bootloader are
1- Start
2- Reboot bootloader
3- Recovery mode
4- Power off
5- Barcodes

malibusa said:
Hi,
thanks for your reply,
let me make sure, that i understood you clearly,
when i boot into bootloader, and select the recovery mode,
it get rebooted, shows Google “in white” then restart again, and again in same loop exactly as if i booted normally, not into the bootloader
as i read in other posts, i should expect the device to show me a confirmation message, or something similar,
but in my case, nothing at all, restart, and keep restarting
The options i have with bootloader are
1- Start
2- Reboot bootloader
3- Recovery mode
4- Power off
5- Barcodes
Click to expand...
Click to collapse
In bootloader mode, not recovery try flashing the bootloader and radio like I said.

Hi... RMA your phone... Contact google or Huawei depending where you bought your N6P.
Check this link. A lot of people seem to be in the same situation at the moment:
https://forum.xda-developers.com/nexus-6p/help/boot-loop-death-nexus-6p-t3533528

You're in the same boat as a few of us.
Phone is stuck in a bootloop, won't go to recovery. Only boots to fastboot, but your bootloader is locked so you cannot boot/flash any zips, even official ones. That means no recovery access, which means no adb commands. ADB commands *might* be useful to reboot into EDL mode for QFIL flashing, or for wiping partitions. Problem is - if that bootloader wasn't unlocked, it's not going to be. You need to check "Allow OEM unlocking" in settings BEFORE the phone dies, otherwise you will not be able to unlock the bootloader and thereby reflash the phone.
In a perfect world - we could use EDL mode (or something) to use QFIL/MiFlash to completely rewrite the partitions and MAYBE bring the phone back to life, but the stock bootloader does not allow access to EDL. (tried the custom fastboot.exe meant to send the reboot-edl command, didn't work). If someone can figure out the JTAG pins, we might be able to move forward by purposely bricking it to QHUSB_BULK mode.
The thing is - we don't know why the phones started bootlooping in the first place. For some people, a simple cache wipe/factory reset fixes the loop and away they go. HOWEVER, those of us stuck in fastboot mode with a locked bootloader have no way to erase/wipe/format/write partitions, and even if we could, there's no guarantee it was a software issue that caused the loop in the first place.
TL/DR - You have a locked bootloader and cannot access recovery mode, this means you won't be able to flash/wipe/format partitions or images. Best bet is to contact Huawei/Google, but you'll need the original receipt. If that's not an option for you, you're gonna have to wait until the XDA geniuses out there grant us some answers.
Here's a related thread with some deep info:
https://forum.xda-developers.com/nexus-6p/general/qpst-qfil-answer-to-issues-t3455779

singularoctopi said:
You're in the same boat as a few of us.
Phone is stuck in a bootloop, won't go to recovery. Only boots to fastboot, but your bootloader is locked so you cannot boot/flash any zips, even official ones. That means no recovery access, which means no adb commands. ADB commands *might* be useful to reboot into EDL mode for QFIL flashing, or for wiping partitions. Problem is - if that bootloader wasn't unlocked, it's not going to be. You need to check "Allow OEM unlocking" in settings BEFORE the phone dies, otherwise you will not be able to unlock the bootloader and thereby reflash the phone.
In a perfect world - we could use EDL mode (or something) to use QFIL/MiFlash to completely rewrite the partitions and MAYBE bring the phone back to life, but the stock bootloader does not allow access to EDL. (tried the custom fastboot.exe meant to send the reboot-edl command, didn't work). If someone can figure out the JTAG pins, we might be able to move forward by purposely bricking it to QHUSB_BULK mode.
The thing is - we don't know why the phones started bootlooping in the first place. For some people, a simple cache wipe/factory reset fixes the loop and away they go. HOWEVER, those of us stuck in fastboot mode with a locked bootloader have no way to erase/wipe/format/write partitions, and even if we could, there's no guarantee it was a software issue that caused the loop in the first place.
TL/DR - You have a locked bootloader and cannot access recovery mode, this means you won't be able to flash/wipe/format partitions or images. Best bet is to contact Huawei/Google, but you'll need the original receipt. If that's not an option for you, you're gonna have to wait until the XDA geniuses out there grant us some answers.
Here's a related thread with some deep info:
https://forum.xda-developers.com/nexus-6p/general/qpst-qfil-answer-to-issues-t3455779
Click to expand...
Click to collapse
I'm stuck with a black screen and QFIL and XiaoMiFlash won't work. My bootloader is unlocked but I can't get to fastboot. Screen is always black but Quallcomm HS-USB QDLoader 9008 appears in device manager. No red light or vibration when connecting the phone.

vcharette said:
I'm stuck with a black screen and QFIL and XiaoMiFlash won't work. My bootloader is unlocked but I can't get to fastboot. Screen is always black but Quallcomm HS-USB QDLoader 9008 appears in device manager. No red light or vibration when connecting the phone.
Click to expand...
Click to collapse
Have you read this thread: https://forum.xda-developers.com/nexus-6p/general/howtos-debrick-nexus-6p-stuck-edl-9008-t3552838
Maybe try asking here, explaining the things you tried.

Related

Remove ClockworkMod Recovery and relock after bricked

So I tried to update to KitKat 4.4 and was never able to get passed the loading screen. I booted into ClockworkMod Recovery and wiped everything and now the device will not go passed the Google loading screen. The device is no longer recognized when I plug into the computer and I cannot access through Wugs.
I called Google and they are sending out an RMA for this device (I did not tell them it was unlocked) and they are sending out a replacement.
Is there anyway that I can remove ClockworkMod Recovery and re-lock this device without being able to access the device through a computer?
BrianXP7 said:
Whoa, RMA's should be only used for last resort bootloader bricks! Since you still have the bootloader ("Google" logo at startup), hold Power + Volume Down to enter Fastboot mode and try reflashing the factory images. Just to be safer, use the Universal Naked Drivers and skip with bootloader image. Don't forget to have the ADB and Fastboot binaries in the same folder. I wouldn't recommend toolkits as they don't expose new users with these situations.
If you need anything else, let me know. If I completely missed on what you needed, sorry about that.
Also, just as long as the bootloader update isn't interrupted or type "fastboot erase bootloader" you should be fine without an RMA.
Click to expand...
Click to collapse
thanks for the reply.
I am able to boot in recovery mode on the device and this is recognized by Wugs as "ADB - device on". When I attempt any flash, it checks Fastboot status and I receive notification that the "Fastboot device was not found". I cannot find a compatible driver when I am in fastboot mode running on a Windows 7 x64 machine.
Any idea on how I can get this N7 to function, return to stock, or at least remove ClockworkMod and lock the bootloader so I can RMA?

A2017U B19 soft bricked after botched LineageOS install

Alright, yesterday I decided to root my phone and install LineageOS through bkores' Axon 7 toolkit, starting from a A2017U on B19. Unlocked the bootloader, rooted, flashed TWRP with no problems. Then, I was a dumbass, and flashed LineageOS without first installing the Universal Bootloader or appropriate modem, which resulted in only being able to access the Fastboot and Recovery menus. Then, I panicked and decided to be an even bigger dumbass and locked the bootloader, which has lead me to this point.
For now, when I try to start the phone "normally," it just cycles through the screen with the blue ZTE logo a few times.
I can't get into EDL mode no matter what I try- I even hacked together a deep flash cable.
I can get into Fastboot mode if I hold down both volume buttons as soon as the ZTE screen pops up. From there, I can select "Start," which just takes me to the first boot loop, "Restart bootloader," which just takes me back into Fastboot, "Recovery mode," which doesn't take me to recovery mode and only puts me in the first boot loop, and "Power off," which does exactly what it says it does.
Device Manager recognizes it as "Android Sooner Single ADB Interface" when it's plugged in Fastboot mode. When not in Fastboot mode, it's recognized as "Handset Diagnostic Interface(DFU) (COM3)," with a model of "QUSB__BULK". Typing "adb devices" into the command line results in no connection in either mode.
Miflash recognizes it as a device when plugged in Fastboot, but any attempts to flash anything results in an error message saying "can not found file flash_all_except_storage.bat".
I've tried pretty much every method to restore it back to a usable state- Axon7Toolkit, MiFlash, axon7tool, all with no luck. All of the other threads on here with people in similar situations seem to be for those with AU2017G models, which hasn't helped. Is there anything I can do, or is it FUBAR?
Thank you in advance for the help.
Americ said:
Alright, yesterday I decided to root my phone and install LineageOS through bkores' Axon 7 toolkit, starting from a A2017U on B19. Unlocked the bootloader, rooted, flashed TWRP with no problems. Then, I was a dumbass, and flashed LineageOS without first installing the Universal Bootloader or appropriate modem, which resulted in only being able to access the Fastboot and Recovery menus. Then, I panicked and decided to be an even bigger dumbass and locked the bootloader, which has lead me to this point.
For now, when I try to start the phone "normally," it just cycles through the screen with the blue ZTE logo a few times.
I can't get into EDL mode no matter what I try- I even hacked together a deep flash cable.
I can get into Fastboot mode if I hold down both volume buttons as soon as the ZTE screen pops up. From there, I can select "Start," which just takes me to the first boot loop, "Restart bootloader," which just takes me back into Fastboot, "Recovery mode," which doesn't take me to recovery mode and only puts me in the first boot loop, and "Power off," which does exactly what it says it does.
Device Manager recognizes it as "Android Sooner Single ADB Interface" when it's plugged in Fastboot mode. When not in Fastboot mode, it's recognized as "Handset Diagnostic Interface(DFU) (COM3)," with a model of "QUSB__BULK". Typing "adb devices" into the command line results in no connection in either mode.
Miflash recognizes it as a device when plugged in Fastboot, but any attempts to flash anything results in an error message saying "can not found file flash_all_except_storage.bat".
I've tried pretty much every method to restore it back to a usable state- Axon7Toolkit, MiFlash, axon7tool, all with no luck. All of the other threads on here with people in similar situations seem to be for those with AU2017G models, which hasn't helped. Is there anything I can do, or is it FUBAR?
Thank you in advance for the help.
Click to expand...
Click to collapse
Ouch, DFU brick. I don't know if you can really do anything from fastboot, maybe unlock the bootloader again? fastboot oem unlock?
I'm wondering how you managed to lock the bootloader without having been warned tgat your phone would become a brick if ANYTHING was out of place (for example a custom recovery, or root) Every guide to relock has a big flashy warning. Did you use the toolkit to relock? If that's the case I'd say @bkores needs to add a warning to the option, maybe something like the "Type yes to continue" kind.
Okay, on to the other stuff. There are two ways to fix a DFU brick: send to ZTE, say it broke itself (Or be honest and pay $80, your choice) or take apart your device (I did this on my A2017G, with a lot of care and patience it works). There might be a solution that uses fastboot, but I'm unsure about flashing a system with fastboot, maybe it is possible though. You want EDL mode to use MiFlash and reinstall a working system on the phone. You are on DFU mode instead of EDL. google "4th category brick repair guide" for the actual guide that you need to use (it's here in XDA but it's faster to find via google). Just a small comment:
To download the stuff easily without having to translate the whole 4PDA page (the guys who made the method are Russians from 4pda), find the "MiFlash and Drivers" link. Open it, you'll find a bunch of spoilers. If you open them all you'll see that the actual files that you need to use have non-cyrillic titles, so download the A2017U_FULL_EDL (like 3 GB), and the MiFlash and drivers. Once you have everything you can simply follow the XDA guide and get it up and running again. Remember to keep the battery plugged to the motherboard though, it won't work otherwise

re-locking boot loader & restore

How can I relock the boot loader and restore my Stylo 2 to factory default? Provider is T-mobile.
fastboot flash oem lock.
Note however if you used twrp this will brick your device unless you flash the original recovery first. Provided you got the kdz or LG bridge you should be able to just lock put in download mode and use the repair recovery option.I'm not responsible if you brick your device. Good luck
Frosthaxx said:
fastboot flash oem lock.
Note however if you used twrp this will brick your device unless you flash the original recovery first. Provided you got the kdz or LG bridge you should be able to just lock put in download mode and use the repair recovery option.I'm not responsible if you brick your device. Good luck
Click to expand...
Click to collapse
I had used LG Bridge to reflash my phone so I believe that I have original recovery on the phone. How can I verify?
When I enter fastboot flash oem lock I get < waiting for device> on my terminal screen and thats it?
Once you have the phone wiped completely back to default (including recovery) with the LG tools. Enable developer mode, and then enable USB debugging. While it is plugged into your PC navigate to the folder where you have the ADB applications in CMD or add the location to your Environment variables. The latter will allow you to launch ADB/fastboot commands from any location in CMD. I definitely suggest this. With your phone connected run "adb devices" to make sure that it sees your device. Then run "adb reboot-bootloader" to reboot into the bootloader. While on that screen run the command "fastboot flashing lock_critical". It should prompt OKAY then give the time it took and also that all of the user data was deleted. Then finish up by typing "fastboot reboot". That will put the phone back into a normal mode. Boom, you are done.
Help
When I use the fastboot oem lock, at the moment when I power on the phone in the screen appears the text "Your device has failed a routine safety check and will not boot.
This may be a temporary problem.If this message occurs rerepeatedly, visit this link on another device and refer to the Red case: g.co/ABH
I have two days looking for the solution, and I didn't found anything

phone bricked? help!

I decided to update my old oneplus 2 to lineageos 15.1 with, but when I tried to flash the file with TWRP, it shows an error. Since the TWRP version I was using was old, I decided to update it first. Keep in mind at this point i had completely wiped my device. So, I downloaded the "twrp-3.2.1-0-kenzo.img" file, as per a youtube video where the dude managed to flash the update successfully, and gave it a go. It showed up as successful. Then i shut the whole device off, and tried to boot back in to recovery to flash the ROM again, but the thing won't boot. It's stuck on this boot screen (with the oneplus logo and 'powered by android' at the bottom), and refuses to go further. I'm stuck in a situation with the phone having no OS, no recovery and the thing won't show up when I connect it to the pc either. Well, the pc makes the 'device connected' notification sound when I plug it in, but nothing shows up on the file explorer or the device manager.
That's my dilemma, please i need help!
Thanks in advance.
inwarse said:
I decided to update my old oneplus 2 to lineageos 15.1 with, but when I tried to flash the file with TWRP, it shows an error. Since the TWRP version I was using was old, I decided to update it first. Keep in mind at this point i had completely wiped my device. So, I downloaded the "twrp-3.2.1-0-kenzo.img" file, as per a youtube video where the dude managed to flash the update successfully, and gave it a go. It showed up as successful. Then i shut the whole device off, and tried to boot back in to recovery to flash the ROM again, but the thing won't boot. It's stuck on this boot screen (with the oneplus logo and 'powered by android' at the bottom), and refuses to go further. I'm stuck in a situation with the phone having no OS, no recovery and the thing won't show up when I connect it to the pc either. Well, the pc makes the 'device connected' notification sound when I plug it in, but nothing shows up on the file explorer or the device manager.
That's my dilemma, please i need help!
Thanks in advance.
Click to expand...
Click to collapse
You downloaded the KENZO (this is not oneplus2! ) TWRP and flashed it on another phone (oneplus2), just normal that it doesn't work and your phone is messed up.
If you can enter fastboot (vol up and power button to boot) you can rescue your phone:
-enter fastboot (vol up + power, while phone is completely off, u can also hold it until you can see "fastboot" written on the screen)
-connect device to a computer with fastboot installed
-type "fastboot oem unlock" into a terminal/cmd window if there is no error, you are good to go, otherwise your bootloader relocked, use this thread to recover
-if your bootloader is still unlocked, download the ONEPLUS2 TWRP IMG, ALWAYS make sure to only flash the roms, kernels, recoveries or zips for YOUR phone otherwise you can really DESTROY your phone!
-now type into terminal/cmd: "fastboot flash recovery *drag the oneplus2 twrp image into terminal/cmd window* and hit enter
-use vol down + power to reboot phone into recovery and wipe all partitions
-Install a ONEPLUS2 ROM of your choice
If something is not clear, use google, because this is most likely basic stuff you have to know when flashing your phone
I can in fact go to fastboot mode by holding the power+volume up keys. When I the phone to my pc it does show a fastboot device (9597b869 fastboot). What do i do from here?
inwarse said:
I can in fact go to fastboot mode by holding the power+volume up keys. When I the phone to my pc it does show a fastboot device (9597b869 fastboot). What do i do from here?
Click to expand...
Click to collapse
As I wrote above (it's a step-by-step guide, u only have to READ )
-connect device to a computer with fastboot installed
-type "fastboot oem unlock" into a terminal/cmd window if there is no error, you are good to go, otherwise your bootloader relocked, use this thread to recover
-if your bootloader is still unlocked, download the ONEPLUS2 TWRP IMG, ALWAYS make sure to only flash the roms, kernels, recoveries or zips for YOUR phone otherwise you can really DESTROY your phone!
-now type into terminal/cmd: "fastboot flash recovery *drag the oneplus2 twrp image into terminal/cmd window* and hit enter
-use vol down + power to reboot phone into recovery and wipe all partitions
-Install a ONEPLUS2 ROM of your choice
wertus33333 said:
As I wrote above (it's a step-by-step guide, u only have to READ )
-connect device to a computer with fastboot installed
-type "fastboot oem unlock" into a terminal/cmd window if there is no error, you are good to go, otherwise your bootloader relocked, use this thread to recover
-if your bootloader is still unlocked, download the ONEPLUS2 TWRP IMG, ALWAYS make sure to only flash the roms, kernels, recoveries or zips for YOUR phone otherwise you can really DESTROY your phone!
-now type into terminal/cmd: "fastboot flash recovery *drag the oneplus2 twrp image into terminal/cmd window* and hit enter
-use vol down + power to reboot phone into recovery and wipe all partitions
-Install a ONEPLUS2 ROM of your choice
Click to expand...
Click to collapse
i tried to follow the guide. but the bootloader, as per you description is relocked. the download link for the driver you provided shows up as empty/no longer available. that's where i'm getting stuck.
P.S, i can enter fastboot mode on the phone via power+volume up.
thanks for the help so far, i can't seem to find much help other than from you so far
Oh, the link is dead, sry for that. try this one (GDrive links are up and working).
inwarse said:
i tried to follow the guide. but the bootloader, as per you description is relocked. the download link for the driver you provided shows up as empty/no longer available. that's where i'm getting stuck.
P.S, i can enter fastboot mode on the phone via power+volume up.
thanks for the help so far, i can't seem to find much help other than from you so far
Click to expand...
Click to collapse
so i managed to get into qualcomm mode, updated the drivers, and ran "MSM8994DownloadTool.exe" in administrator mode. it went as it's outlined in your guide. however, at the end of that process, the phone got stuck in a bootloop (the oneplus logo flashes for a moment and restarts). and can't get into qualcomm mode now, since when i connect the usb to the pc while the phone off, it lights the display (to show that it's charging, i think). any way back from this?
(i can still get into fastboot mode)
inwarse said:
so i managed to get into qualcomm mode, updated the drivers, and ran "MSM8994DownloadTool.exe" in administrator mode. it went as it's outlined in your guide. however, at the end of that process, the phone got stuck in a bootloop (the oneplus logo flashes for a moment and restarts). and can't get into qualcomm mode now, since when i connect the usb to the pc while the phone off, it lights the display (to show that it's charging, i think). any way back from this?
(i can still get into fastboot mode)
Click to expand...
Click to collapse
Do you still have TWRP? If yes go to TWRP and shut down the phone there, afterwards you should be able to enter qualcomm mode again.
otherwise you have to try (i think 10s power button will shut the device completely down). You should be able to enter qualcomm mode if the device is fully shut off (your scenario sounds as if the device is not fully shut off when u connect it to the pc).
Just to go sure: You are absolutely sure to have a oneplus2, are you?
inwarse said:
so i managed to get into qualcomm mode, updated the drivers, and ran "MSM8994DownloadTool.exe" in administrator mode. it went as it's outlined in your guide. however, at the end of that process, the phone got stuck in a bootloop (the oneplus logo flashes for a moment and restarts). and can't get into qualcomm mode now, since when i connect the usb to the pc while the phone off, it lights the display (to show that it's charging, i think). any way back from this?
(i can still get into fastboot mode)
Click to expand...
Click to collapse
Could you resolve the issue?
wertus33333 said:
Could you resolve the issue?
Click to expand...
Click to collapse
nope. kept running into issue after issue, so got dejected and gave up.

Nexus 7 2012 stuck in APX mode

I presume I'm stuck, but just in case…
I used TWRP to flash the latest LineageOS, and for some reason the bootloader got erased/corrupted (I'm not entirely sure how this can happen).
As a result, the tablet is now stuck in APX mode when booting up. Inconvenient to say the least…
I can still access TWRP, but any attempt to access Fastboot (ie adb reboot bootloader) results into the unit getting into NVIDIA recovery mode (ie APX)
And of course I don't have a backup of the boot keys.
Since I can access TWRP, is there anyway I can get access to the boot keys to reconstruct my bootloader ?
Regards
Ashram56 said:
I presume I'm stuck, but just in case…
I used TWRP to flash the latest LineageOS, and for some reason the bootloader got erased/corrupted (I'm not entirely sure how this can happen).
As a result, the tablet is now stuck in APX mode when booting up. Inconvenient to say the least…
I can still access TWRP, but any attempt to access Fastboot (ie adb reboot bootloader) results into the unit getting into NVIDIA recovery mode (ie APX)
And of course I don't have a backup of the boot keys.
Since I can access TWRP, is there anyway I can get access to the boot keys to reconstruct my bootloader ?
Regards
Click to expand...
Click to collapse
Hi, Ashram56...
Just to confirm, we are talking about the Nexus 7 (2012) tablet here? Because if you can still access TWRP, the bootloader is not 'dead'. If the bootloader were corrupted or erased, the device would not boot at all... ever! Not even in TWRP!
If it is a Nexus 7, you should be able to manually boot the device into its bootloader by long pressing and holding the volume down button, and at the same time, press the power button.
With regard to doing it via a command prompt, I think you need...
Code:
fastboot reboot bootloader
...as ADB commands only work when Android is fully booted.
Hope this helps.
Rgrds,
Ged.
GedBlake said:
Hi, Ashram56...
Just to confirm, we are talking about the Nexus 7 (2012) tablet here? Because if you can still access TWRP, the bootloader is not 'dead'. If the bootloader were corrupted or erased, the device would not boot at all... ever! Not even in TWRP!
If it is a Nexus 7, you should be able to manually boot the device into its bootloader by long pressing and holding the volume down button, and at the same time, press the power button.
With regard to doing it via a command prompt, I think you need...
Code:
fastboot reboot bootloader
...as ADB commands only work when Android is fully booted.
Hope this helps.
Rgrds,
Ged.
Click to expand...
Click to collapse
Yes this is a Nexus 7 2012
However that's the point: I can boot TWRP (hence adb mode), however if I select "adb reboot bootloader", or if I select "Bootloader" using the Power+Volume Down menu, I don't get into fastboot, I only get into APX, which is recovery
I was under the impression that the bootloader was corrupted, I'm glad this is not the case. Now I just need to figure out how to recover from where I am at this point
And to clarify even further:
- I tried to use TWRP to flash boot.img that I extracted from LineageOS, still boots into recovery
- Did the same with the recovery image, same behaviour
- I realized that I had performed (my bad) a complete "internal storage" wipe, after flashing originally, which might have caused the issue
Bootloader indeed seems to be intact, the info page on the recovery menu (ie before booting TWRP) states 4.23
Ashram56 said:
Yes this is a Nexus 7 2012
However that's the point: I can boot TWRP (hence adb mode), however if I select "adb reboot bootloader", or if I select "Bootloader" using the Power+Volume Down menu, I don't get into fastboot, I only get into APX, which is recovery
I was under the impression that the bootloader was corrupted, I'm glad this is not the case. Now I just need to figure out how to recover from where I am at this point
Click to expand...
Click to collapse
I suspect some confusion of technical terms is going on here.
Can you as describe, as precisely as possible, exactly what your Nexus 7 is displaying, when you enter what you think is, or might be, APX mode.
A picture/photograph would be even better.
APX/nvFlash mode is NOT Recovery. These are very, very different things.
Recovery is either the devices Stock Recovery, or a Custom Recovery, such as TWRP or CWM.
Rgrds,
Ged.
---------- Post added at 07:07 PM ---------- Previous post was at 06:52 PM ----------
Ashram56 said:
And to clarify even further:
- I tried to use TWRP to flash boot.img that I extracted from LineageOS, still boots into recovery
- Did the same with the recovery image, same behaviour
- I realized that I had performed (my bad) a complete "internal storage" wipe, after flashing originally, which might have caused the issue
Bootloader indeed seems to be intact, the info page on the recovery menu (ie before booting TWRP) states 4.23
Click to expand...
Click to collapse
OK, just seen this post.
You dont use TWRP to flash .img files, you use fastboot, so for example, you'd use the following command lines...
Code:
fastboot flash boot [name-of-boot-file].img
...or...
Code:
fastboot flash recovery [name-of-recovery-file].img
...with the Nexus 7 booted into fastboot mode and USB connected to a laptop or a PC.
Rgrds,
Ged.
Hi, again Ashram56...
Some further thoughts regarding your situation...
Ashram56 said:
Bootloader indeed seems to be intact, the info page on the recovery menu (ie before booting TWRP) states 4.23
Click to expand...
Click to collapse
So that would be on the fastboot menu then, and not the recovery menu. I'm not trying to be needlessly pedantic here, but when dealing with this kind of thing, and when asking for advice, it's important to use the correct terms, otherwise confusion can arise.
Anyhow, your reporting of this indicates that your Nexus 7's bootloader is alive and well, which means the device is almost certainly recoverable.
Furthermore, bootloader v4.23 is the latest and the very last bootloader version this device will ever receive.
Whatever you chose to do, I'd strongly recommend against reflashing the bootloader again, as this process is the 'Achilles Heel' of the Nexus 7, and it's a potential terminal weakness. A bad bootloader flash, perhaps via a dodgy USB connection, can corrupt the bootloader, and render the device permanently hardbricked. And the only realistic solution to that is a motherboard replacement.
And which brings me to this...
Ashram56 said:
And of course I don't have a backup of the boot keys.
Since I can access TWRP, is there anyway I can get access to the boot keys to reconstruct my bootloader ?
Click to expand...
Click to collapse
I'm aware that you mentioned in your original post, something you called 'boot keys'. I assume you refer to the Nexus 7 'flatline' procedure for generating bootloader 'blobs', described here...
https://forum.xda-developers.com/showthread.php?t=2455927
Such 'blobs' can ONLY be used on the original Nexus 7 with which they were originally generated. They are NOT transferable from one N7 to another N7.
Running the 'flatline' procedure is a fairly high risk venture, and requires a good knowledge and a high level of familiarity with using fastboot commands, because it involves flashing a special build of the bootloader. I ran it myself, a few years ago, and it's a pretty nerve wracking experience, wondering if your Nexus 7 will ever boot again!
Mine did, and I now have my N7 bootloader 'blobs', stored on my laptop ~ but I have absolutely no idea at all, if they'd be of any use should I have need to dig myself out of an APX shaped hole!
Fortunately that hasn't happened yet, and my 'blobs' will now likely forever remain untested, as I rarely use my Nexus 7 these days.
------------------------------------
Ashram56 said:
I used TWRP to flash the latest LineageOS, and for some reason the bootloader got erased/corrupted (I'm not entirely sure how this can happen
Click to expand...
Click to collapse
...And it can't happen!. A TWRP flash of a Custom ROM, such as LineageOS, goes nowhere near the bootloader partition. It doesn't touch it at all. Same with a TWRP Nandroid restore. Bootloader partition is left alone, unmodified and untouched.
------------------------------------
Anyhow, and in conclusion, it sounds like your bootloader is still working, and you should therefore be able to recover the device.
The easiest way of doing this, is to download a Google Factory Stock image for the Nexus 7 and flash it via fastboot, and which you can find here...
https://developers.google.com/android/images#nakasi
------------------------------------
Good luck with getting your Nexus 7 up and running again, and I hope this helps.
Rgrds,
Ged.
You are correct to ask to be very precise, as words have different meaning, and can lead to confusion, as is the case here
I used the word "recovery" by mistake (I'm actually in HW Embedded design, and APX mode is called "recovery" mode in a lot of Tegra related literature). So to be clear, I will only refer to APX mode.
APX mode is essentially a mode the chip enters when it cannot find a valid bootloader, or when the bootloader fails to load a valid kernel (see similar details here for those who really want to get their head spinning: http://developer.nvidia.com/embedded/dlc/jetson-fuse-burning-secure-boot-28-2-ga , need registration to access the document though). You can also access this mode by asserting some HW pins at boot up (which are not exposed on the Nexus 7 2012 anyway)
Screen is black in this case, since the kernel has not loaded
Symptoms I have:
- I can access the "Boot select" menu, through Power+Volume- menu
- I can access from the "Recovery", which launches TWRP
- If I use the "Reboot" option from TWRP, or the "Bootloader" option from the "Boot select" menu in 1/, I get a black screen, and the tablet appears to be in APX mode (seen through simple linux lsusb command)
It turns out that in "some" instances I was able to actually turn on the tablet and boot the OS, but I can't figure what sequences (ie I can't find a reproducible way of booting correctly, 9 times out of 10 I get into APX mode).
I'll try to figure out further what the heck is going on. My suspicion is that the bootloader is attempting to load the kernel, and the first copy is corrupted. In most Tegra implementations, this should be covered through redudancy of the kernel at multiple locations (same for bootloader actually), but I'm not knowledgeable enough about Android to determine if this is the case as well here.
Thanks for the help in any case
And to add to that:
when in "Boot select" menu, units does appear in Fastboot mode, however "fastboot reboot bootloader" gets me into APX mode (black screen, tablet seen as APX device, fastboot and adb not functional), same as booting to Bootloader from TWRP or "select" menu.
I'm quite puzzled...
Just a note: one time out of 10 I can boot into the OS
I'll settle for that for the moment
Reviving this 4y old thread...
So, recently I unburied my Nexus 7, to use it as a secondary device for some home automation application.
Took me a while to find my bearings again, but here's a summary of where I stand:
- If I power on normally (ie power button) the tablet for the first time or do a reboot (either through the UI or the adb command), it enters "NVIDIA Tegra recovery mode", ie device driver appears as APX
- When is this mode, if I press the power button for 10s or so it powers off
- When fully off, if I simultaneously press Volume - + power button, I can enter the bootloader mode (ie Fastboot mode), with the small droid, the info text at the bottom left, and a big "Start" button on the upper right corner.
Info reported in the bottom left in that case:
Fastboot mode
Product name - grouper
Variant name - grouper
HW version - ER3
Bootloader version - 4.23
Basedband version - N/A
Serial Number - sequence of numbers
Signing - not defined yet
Lock state - Unlocked
- in this mode, the volume keys do not have any effect, I can't select anything, only "Start" is available. I can indeed "Start" the tablet using the power button
It starts Android (in my case LineageOS), but in safe mode only, so limited functionality
And I'm stuck, since I can't use the tablet.
I know it's a very old thread, but if anyone has any clue on how to resolve this, I'm interested
Regards
[EDIT] Some additionnal data
- First, looks like my volume buttons are actually broken. I don't get any response inside Android UI, that would explain why I can't select anything in when in fastboot besides "Start" option
- I reverted back to the stock image, but I'm still stuck in safe mode.
I can't install LineageOS back, since I can't navigate in fastboot menu and access twrp (unless I can do that using a fastboot command) ?

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