Remove ClockworkMod Recovery and relock after bricked - Nexus 7 Q&A, Help & Troubleshooting

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?

Related

nexus 6p doesn't boot, with error when trying to unlock

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.

Stuck in Bootloop

US996 Unlocked, stock rom. I was in XDA Forums and saw there were app updates, one being Play Store. I updated. When I tried to get into Play Store, the message "this version of play store is incompatible with your device, go to settings and disable app update (or something like that). I tried but the app was not listed in settings. I tried to reboot and now the phone bootloops. All I can get is the warning that the software cannot be checked for corruption and then a quick display of the LG logo, then screen off, and then LG logo again and then warning screen, etc. If I try to reboot into recovery I get the Factory data reset screens and I answer both "yes" and the phone goes into adb mode.. From adb mode I can fastboot reboot, which puts me back into the above loop, or fastboot bootloader, which merely returns me to the adb screen. What can I do now?
Maybe try relocking the bootloader. I am pretty sure (someone correct me if I am wrong) that that pop-up of the "cannot check for corruption" usually only shows when the bootloader is unlocked.
XP_1 said:
Maybe try relocking the bootloader. I am pretty sure (someone correct me if I am wrong) that that pop-up of the "cannot check for corruption" usually only shows when the bootloader is unlocked.
Click to expand...
Click to collapse
Is that even possible? Don't know how to do it.
PhoneBull said:
Is that even possible? Don't know how to do it.
Click to expand...
Click to collapse
Try entering
Code:
fastboot oem device-info
into Fastboot on your computer to see if it says it is unlocked when in fastboot mode.
XP_1 said:
Try entering
Code:
fastboot oem device-info
into Fastboot on your computer to see if it says it is unlocked when in fastboot mode.
Click to expand...
Click to collapse
I get "FAILED (remote: unknown command)"
Do you have fastboot installed on your computer? (Something you would have had to have intentionally installed) If not google Minimal Fastboot /ADB and install it, enter the supposed ADB screen you are talking about and see if it makes contact with your phone.
XP_1 said:
Do you have fastboot installed on your computer? (Something you would have had to have intentionally installed) If not google Minimal Fastboot /ADB and install it, enter the supposed ADB screen you are talking about and see if it makes contact with your phone.
Click to expand...
Click to collapse
I have the fastboot on the PC that I used to unlock the bootloader.. I enter fastboot on the PC via the administrative command prompt. With the phone in the fastboot mode, I type "fastboot devices" on the PC and get a proper response (LGUS996ab**** fastboot). If I enter ""fastboot reboot" I get the bootloop. If I enter "fastboot bootloader" I wind up in Fastboot Mode on the phone again. I was hoping there was a "fastboot recovery" command but there doesn't seem to be. I don't know what to do next. I am not all that familiar with what can be done from fastboot. My only experience with it was when I unlocked the phone. I am desperate!
Okay, so if you do not have TWRP installed on your phone, then I don't know if you can save your data. You can try to
Code:
fastboot erase cache
and see if it helps, or if not and just reset the device fastboot oem lock I think. Maybe ask around in the unlocking help threads or perhaps someone with more knowledge will chime in. If none of this works, then there are some instructions on how to get your phone back to stock in the News and Guides section.
EDIT: Maybe try the power+volume down. It may work? I have tried it and never got it to successfully work. But you can try it.
XP_1 said:
Okay, so if you do not have TWRP installed on your phone, then I don't know if you can save your data. You can try to
Code:
fastboot erase cache
and see if it helps, or if not and just reset the device fastboot oem lock I think. Maybe ask around in the unlocking help threads or perhaps someone with more knowledge will chime in. If none of this works, then there are some instructions on how to get your phone back to stock in the News and Guides section.
Click to expand...
Click to collapse
Thanks for your help. I DO have TWRP installed and have used it often for backups. But now the only way I know to TRY to get to it is by the power/vol down until LG logo, then release/repress power button sequence but this just gets me into fastboot mode. II have some recent backups saved on my micro SD card - is there any way to flash one of them through fastboot if I load one onto the PC?
Yeah. My bad. Okay, so how I get into TWRP is through the EasyRecowvery.
Go ahead and download it from Git-Hub (1.3b3).
Now extract it and run the cmd program. Enter 5. which is extras and stuff and then enter 5 again in the sub menu which will let you boot into recovery. When you are in recovery, and plugged into your computer, you should be able to either flash or drag and drop like a flash drive on the the phone. Hope that helps a little bit.
XP_1 said:
Yeah. My bad. Okay, so how I get into TWRP is through the EasyRecowvery.
Go ahead and download it from Git-Hub (1.3b3).
Now extract it and run the cmd program. Enter 5. which is extras and stuff and then enter 5 again in the sub menu which will let you boot into recovery. When you are in recovery, and plugged into your computer, you should be able to either flash or drag and drop like a flash drive on the the phone. Hope that helps a little bit.
Click to expand...
Click to collapse
I don't have T-Mobile. I have Verizon Wireless on the US996. Will that work?
PhoneBull said:
I don't have T-Mobile. I have Verizon Wireless on the US996. Will that work?
Click to expand...
Click to collapse
Since you are only rebooting into recovery and not flashing anything it might. If not, it will just fail and not harm anything. Last thing to try is the
Code:
adb reboot recovery
which is the only thing I can think of and I think you already tried it. Otherwise you will need to just go stock.

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

Unable to enter fastboot mode after flashing

I have unlocked my phone, hoping to find a fix to USB external camera not being recognized. As a consequence, I am not able to update my system through OTA. Moreover, I am no longer able to enter fastboot mode. Whatever key combination I tried, my phone will do a normal boot. When I power up or I press volume - I only end up doing a normal boot or powering off. If I press all 3 keys together I get into the e-recovery boot, which fails. I have only been able to boot into TWRP after downloading a system update and choosing to install it. With this procedure, the update will not be installed, but I will boot into TWRP. From here, if I choose recovery, I do boot into fastboot, but my fastboot is not recognized by my computer, as it was before. Running either ADB or Fastboot will not reveal any device connected.
pieemme said:
I have unlocked my phone, hoping to find a fix to USB external camera not being recognized. As a consequence, I am not able to update my system through OTA. Moreover, I am no longer able to enter fastboot mode. Whatever key combination I tried, my phone will do a normal boot. When I power up or I press volume - I only end up doing a normal boot or powering off. If I press all 3 keys together I get into the e-recovery boot, which fails. I have only been able to boot into TWRP after downloading a system update and choosing to install it. With this procedure, the update will not be installed, but I will boot into TWRP. From here, if I choose recovery, I do boot into fastboot, but my fastboot is not recognized by my computer, as it was before. Running either ADB or Fastboot will not reveal any device connected.
Click to expand...
Click to collapse
When you use key combinations, you must shutdown your phone first, not reboot or you can boot into system, make sure that usb debugging is turned on, open adb and type "adb reboot bootloader".
DeathBell said:
When you use key combinations, you must shutdown your phone first, not reboot or you can boot into system, make sure that usb debugging is turned on, open adb and type "adb reboot bootloader".
Click to expand...
Click to collapse
Thanks, I followed your instructions but with no success. As soon as I plug into USB it will power on and go on with a normal system boot, no matter how quick I am in typing the command "adb reboot bootloader", which invariably returns "no devices/emulators found", or whether I press the volume - button or not. This also happens when I am in the charging screen (not sure whether this also equals power off).
pieemme said:
Thanks, I followed your instructions but with no success. As soon as I plug into USB it will power on and go on with a normal system boot, no matter how quick I am in typing the command "adb reboot bootloader", which invariably returns "no devices/emulators found", or whether I press the volume - button or not. This also happens when I am in the charging screen (not sure whether this also equals power off).
Click to expand...
Click to collapse
No, you need to boot to Android to use adb.
Is your device bricked or stuck in a bootloop or something?
DeathBell said:
No, you need to boot to Android to use adb.
Is your device bricked or stuck in a bootloop or something?
Click to expand...
Click to collapse
I wouldn’t call it properly bricked, inasmuch as it is actually doing its job. However, It does some strange things: it gets the OTA updates, but when I click on Download and Install, it restarts in the TWRP menu (which I cannot otherwise access. I have 2 TWRP apps installed, which don’t seem to be of any use: official TWRP App and TWRP Manager). When I am in the TWRP menu, I can choose to restart in the bootloader. However, once there, with the green window telling me that my phone is flashed, the phone is still not detected by ADB or Fastboot commands. I don’t know when the bootloader started to be unaccessible because I left the tinkering a couple of months ago, when I realized that nobody so far has had any success in getting a P10 Lite to work with a USB Endoscope.
pieemme said:
I wouldn’t call it properly bricked, inasmuch as it is actually doing its job. However, It does some strange things: it gets the OTA updates, but when I click on Download and Install, it restarts in the TWRP menu (which I cannot otherwise access. I have 2 TWRP apps installed, which don’t seem to be of any use: official TWRP App and TWRP Manager). When I am in the TWRP menu, I can choose to restart in the bootloader. However, once there, with the green window telling me that my phone is flashed, the phone is still not detected by ADB or Fastboot commands. I don’t know when the bootloader started to be unaccessible because I left the tinkering a couple of months ago, when I realized that nobody so far has had any success in getting a P10 Lite to work with a USB Endoscope.
Click to expand...
Click to collapse
Thats normal behaviour, when you have a custom recovery installed and do anything in the stock recovery then it boots you into the custom recovery, it should also boot to TWRP when you do factory reset in the stock recovery. And when your phone isn't detected by fastboot then its probably a adb and fastboot installation issue on your PC, type "fastboot devices" to see if it detects your device. And what do you even want to do in fastboot?
Also are you in Nougat or Oreo?
DeathBell said:
Thats normal behaviour, when you have a custom recovery installed and do anything in the stock recovery then it boots you into the custom recovery, it should also boot to TWRP when you do factory reset in the stock recovery. And when your phone isn't detected by fastboot then its probably a adb and fastboot installation issue on your PC, type "fastboot devices" to see if it detects your device. And what do you even want to do in fastboot?
Also are you in Nougat or Oreo?
Click to expand...
Click to collapse
I am not too sure to have any working recovery at all, right now. If I press all 3 buttons, I get into the Huawei recovery mode, which fails. I am on EMUI 5.1.1 (Nougat) and would like to install a stock recovery to Oreo. If I am able to get to a working bootloader mode, I would like to install this file which seems to be a stock recovery with Oreo (WARSAW L21C432B182_EU_SERVICE_ANDROIDHOST.RU.RAR). Otherwise, I will buy a MicroSD card reader and try copying this installation to the card, which, according to this video (https://www.youtube.com/watch?v=0vDgDXePAR4&feature=youtu.be) should be the last resort, if everything else fails. I would be perfectly happy to return to a working and updated standard EMUI. I'm told that if I installed the OTA version this would not be working correctly on my my phone. According to an app called Rootchecker, my phone is not properly rooted either, but there are a lot of crappy apps out there, so I don't know what to believe.
BTW: I don't believe there is any problem with my adb fastboot installation (on MacOS). It was working earlier on. When I type "fastboot devices", it returns: "waiting for any device"
pieemme said:
I am not too sure to have any working recovery at all, right now. If I press all 3 buttons, I get into the Huawei recovery mode, which fails. I am on EMUI 5.1.1 (Nougat) and would like to install a stock recovery to Oreo. If I am able to get to a working bootloader mode, I would like to install this file which seems to be a stock recovery with Oreo (WARSAW L21C432B182_EU_SERVICE_ANDROIDHOST.RU.RAR). Otherwise, I will buy a MicroSD card reader and try copying this installation to the card, which, according to this video (https://www.youtube.com/watch?v=0vDgDXePAR4&feature=youtu.be) should be the last resort, if everything else fails. I would be perfectly happy to return to a working and updated standard EMUI. I'm told that if I installed the OTA version this would not be working correctly on my my phone. According to an app called Rootchecker, my phone is not properly rooted either, but there are a lot of crappy apps out there, so I don't know what to believe.
BTW: I don't believe there is any problem with my adb fastboot installation (on MacOS). It was working earlier on. When I type "fastboot devices", it returns: "waiting for any device"
Click to expand...
Click to collapse
I still can't uderstand you. Can you boot into Android or not? And Does TWRP work? When you device is softbricked, what did you do to brick it?
At one point you say that you can access fastboot by choosing reboot to bootloader in TWRP and then you say that you have no working recovery at all.
Anyway I can't help you with the fastboot thing then and that file isn't Oreo it's an old version of Nougat, B360 and up is Oreo and also B321 witch is Oreo Beta. You can only flash image files in fastboot anyway as that file needs to be unpacked and put on the dload folder on your sd card.
When you want to get to Oreo you can either use service roms from this thread https://forum.xda-developers.com/p10-lite/development/service-rom-b362-c432-upgrade-o-o-n-o-t3813946, you need to copy the two zip files into the dload folder in your SD card. You can also use HWOTA but that wouldn't work since fastboot isn't working for whatever reason. Or when your custom recovery is working you can use HuRUpdater. But you need to be on the newest version of Nougat B210 or B209 to update as otherwise you may brick your phone.

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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