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Hello all,
Recently I have had a major issue with my nexus 7. About a week ago, it died (ran out of battery) while I was using it. When I attempted to turn it on after charging it, I would get the screen that says google, with unlocked lock icon. The tablet would be frozen at this screen. I left it running until it died again. I was running the latest stable release of cyanogenmod 10 with no problems before when this happened.
By now I had realized that the nexus may have been bricked. I did some googling and found that this is an issue other users have been having when their battery died on android 4.2.2. I attempted to restore the nexus. At this time I was able to access bootloader on the device by holding down all of the buttons at the same time. However, I decided not to restore the nexus, and wait until a time where I would be able to turn all of my attention to the problem. But when I tried to restore the device yesterday, I was not able to access bootloader! I connected the device to my PC (running win8) and it is not recognized. Similarly, trying fastboot restart-bootloader gives me "waiting for device". I am afraid that the bootloader may have been corrupted somehow.
My question is, how can I fix this? Is there a way to reflash the bootloader, or is there something that I am missing? Is there a hardware operation that needs to be performed on the device (battery pull, etc)?
Thanks.
AW: [Q] Help! Nexus 7 not working, may be bricked
I doubt your nexus is bricked. Most likely you entered the APX mode. Hold down the power button for about 6-10 seconds, then it should exit from there.
http://forum.xda-developers.com/wiki/APX_mode
Sent from my Nexus 7 using xda app-developers app
Not working
AndDiSa said:
I doubt your nexus is bricked. Most likely you entered the APX mode. Hold down the power button for about 6-10 seconds, then it should exit from there.
http://forum.xda-developers.com/wiki/APX_mode
Sent from my Nexus 7 using xda app-developers app
Click to expand...
Click to collapse
When I hold down the power button, the device just turns off and comes back on again. The google boot logo shows for a few seconds, then I get a black screen.
patil215 said:
When I hold down the power button, the device just turns off and comes back on again. The google boot logo shows for a few seconds, then I get a black screen.
Click to expand...
Click to collapse
If you get a Google logo, that is a good sign - it means the bootloader is at least partially intact, possibly even in perfect shape.
I would proceed assuming that your battery is completely discharged.
Put the device on the charger overnight and then try starting it up while it is still plugged in to the charger. Hold the vol-down button and the power button continuously until at least one second after the Google logo flashes - this should put the device into fastboot mode if the bootloader is intact.
Something to remember is that Li-Ion batteries have a safety feature that prevents them from charging if the battery voltage gets too low. This is part of the reason why they are shipped with a 50% charge - they can sit that way for months and months only self-discharging at a very very slow rate.
OTOH, if you discharge the battery deeply and then let it sit for a long time afterward - especially if there is something like APX mode draining current - the battery voltage can fall below this "safety threshold voltage" and (even though it is still a "good battery" it can no longer be charged).
I'm not sure it the N7 can be started up while plugged in to only the charger; if it can, disconnecting the battery and trying to power up the device might be a way to discriminate "dead device" from "unchargeable battery".
good luck
I've tried this before
bftb0 said:
If you get a Google logo, that is a good sign - it means the bootloader is at least partially intact, possibly even in perfect shape.
I would proceed assuming that your battery is completely discharged.
Put the device on the charger overnight and then try starting it up while it is still plugged in to the charger. Hold the vol-down button and the power button continuously until at least one second after the Google logo flashes - this should put the device into fastboot mode if the bootloader is intact.
Something to remember is that Li-Ion batteries have a safety feature that prevents them from charging if the battery voltage gets too low. This is part of the reason why they are shipped with a 50% charge - they can sit that way for months and months only self-discharging at a very very slow rate.
OTOH, if you discharge the battery deeply and then let it sit for a long time afterward - especially if there is something like APX mode draining current - the battery voltage can fall below this "safety threshold voltage" and (even though it is still a "good battery" it can no longer be charged).
I'm not sure it the N7 can be started up while plugged in to only the charger; if it can, disconnecting the battery and trying to power up the device might be a way to discriminate "dead device" from "unchargeable battery".
good luck
Click to expand...
Click to collapse
I've tried this before. I still get a google screen, even after fully charging it. Does this mean that the battery has become unusable? How can I fix this?
Then try it again. It takes less time than typing a post into XDA.
There are two ways to try it.
1) Hold both Power & Vol-Down simultaneously, and keep holding them down until at least 4 seconds after the B&W "Google" text appears on the screen
2) Hold only the Power button down continuously, but be ready! Press the Vol-Down button as soon as the Google logo appears! - you only get less than a second to do this. (If you are late, the bootloader tries to boot the boot partition). Also, you need to keep holding the Power button down (3 or 4 seconds) after this - wait long enough that you are convinced that the fastboot screen is not going to occur.
As for the battery, you can pop off the back case and use a voltmeter to CAREFULLY measure the open-circuit voltage. The normal 0%-to-100% voltage range is about 3.6v - 4.15v. Obviously if it won't take a charge then there is a battery issue. BE CAREFUL - avoid doing anything which could short the terminals even momentarily.
bftb0 said:
Then try it again. It takes less time than typing a post into XDA.
There are two ways to try it.
1) Hold both Power & Vol-Down simultaneously, and keep holding them down until at least 4 seconds after the B&W "Google" text appears on the screen
2) Hold only the Power button down continuously, but be ready! Press the Vol-Down button as soon as the Google logo appears! - you only get less than a second to do this. (If you are late, the bootloader tries to boot the boot partition). Also, you need to keep holding the Power button down (3 or 4 seconds) after this - wait long enough that you are convinced that the fastboot screen is not going to occur.
As for the battery, you can pop off the back case and use a voltmeter to CAREFULLY measure the open-circuit voltage. The normal 0%-to-100% voltage range is about 3.6v - 4.15v. Obviously if it won't take a charge then there is a battery issue. BE CAREFUL - avoid doing anything which could short the terminals even momentarily.
Click to expand...
Click to collapse
I've tried holding down the buttons in various configurations at least 50 times already. As for the battery, there is current flowing, so I don't think this is a battery issue. Also worth noting is that if the device completely dies and I plug it in again, the charging battery sign appears (an empty battery slowly filling with white bars). Sometimes the device will give a black screen with little white sparks flickering randomly on it.
Well there have been several posts on here with identical symptoms, where the affected owner later reported that their tablet mysteriously started operating normally.
Unfortunately nothing consistent seems to have emerged from those reports.
You could try disconnecting the battery for a few minutes and reconnecting it to see if that makes any difference.
But whatever you do, you're gonna eventually have to press some buttons & the procedure I suggested is diagnostic for the bootloader, even if the boot or /system partition are borked.
BTW In my experience that battery charging graphic shows the charge state of the battery - does yours show closer to empty or full?
bftb0 said:
Well there have been several posts on here with identical symptoms, where the affected owner later reported that their tablet mysteriously started operating normally.
Unfortunately nothing consistent seems to have emerged from those reports.
You could try disconnecting the battery for a few minutes and reconnecting it to see if that makes any difference.
But whatever you do, you're gonna eventually have to press some buttons & the procedure I suggested is diagnostic for the bootloader, even if the boot or /system partition are borked.
BTW In my experience that battery charging graphic shows the charge state of the battery - does yours show closer to empty or full?
Click to expand...
Click to collapse
Mine shows the battery going from empty to full, like an animation. Also, I'm considering sending in the device for repair but I know that since the bootloader is unlocked it probably wouldn't be free.
Also can you link me to any posts related to this? They might be useful in solving my problem.
Thanks
Were you able to get your computer to recognized your Nexus when you connected it? I had to jump through a bunch of hoops with my Win8 machine to get the driver installed, because it didn't pass Microsoft's signature check. Maybe you can use Wug's toolkit to try to fix it, or at least re-lock the bootloader before sending it in for repair?
codehunter2000 said:
Were you able to get your computer to recognized your Nexus when you connected it? I had to jump through a bunch of hoops with my Win8 machine to get the driver installed, because it didn't pass Microsoft's signature check. Maybe you can use Wug's toolkit to try to fix it, or at least re-lock the bootloader before sending it in for repair?
Click to expand...
Click to collapse
After spending a few hours, I was able to get an adb driver installed onto my computer, I also had to jump through a lot of hoops (I run win8 too). Running adb devices shows the nexus in recovery mode. However, I can't access the bootloader whatsoever. Typing fastboot reboot-bootloader just hangs, and I've tried several toolkits but they just hang. I'm not sure if I can do anything unless I can access bootloader. If you know anything I can do please tell.
patil215 said:
Mine shows the battery going from empty to full, like an animation. Also, I'm considering sending in the device for repair but I know that since the bootloader is unlocked it probably wouldn't be free.
Click to expand...
Click to collapse
By coincidence I was charging mine right now (82%), so I shut it down and looked at that battery animation. (I have the v4.18 bootloader & Dec '12 hardware) First the "lightning bolt" symbol shows up in the battery icon, and the a little later, it performs a "filling the battery up" animation. But here's the important part: when that animation runs on mine, it starts from nearly, but not quite full (mostly white, not all black)- about 82%.
Can't tell exactly from the way you described your situation, but this (again) sounds like your battery is either not charging, or the bq27541 charge controller is reporting the wrong battery state.
Unplug the battery and let it sit for a while before reconnecting. If you have a safe way to measure the battery voltage, do so. You'll know right away if the battery is charged and the charge controller chip is lying.
---------- Post added at 08:14 PM ---------- Previous post was at 07:37 PM ----------
patil215 said:
After spending a few hours, I was able to get an adb driver installed onto my computer, I also had to jump through a lot of hoops (I run win8 too). Running adb devices shows the nexus in recovery mode. However, I can't access the bootloader whatsoever. Typing fastboot reboot-bootloader just hangs, and I've tried several toolkits but they just hang. I'm not sure if I can do anything unless I can access bootloader. If you know anything I can do please tell.
Click to expand...
Click to collapse
That is completely bizzare. The only way that a recovery can be started is via the bootloader. If the bootloader doesn't run, nothing can run. (The recovery is a booted kernel just as with the regular OS). Moreover, you saw the battery screen light up - if a recovery was (still) running, you would think something would show on the screen (although I guess recent versions of TWRP does screen blanking now). Very weird.
bftb0 said:
By coincidence I was charging mine right now (82%), so I shut it down and looked at that battery animation. (I have the v4.18 bootloader & Dec '12 hardware) First the "lightning bolt" symbol shows up in the battery icon, and the a little later, it performs a "filling the battery up" animation. But here's the important part: when that animation runs on mine, it starts from nearly, but not quite full (mostly white, not all black)- about 82%.
Can't tell exactly from the way you described your situation, but this (again) sounds like your battery is either not charging, or the bq27451 charge controller is reporting the wrong battery state.
Unplug the battery and let it sit for a while before reconnecting. If you have a safe way to measure the battery voltage, do so. You'll know right away if the battery is charged and the charge controller chip is lying.
---------- Post added at 08:14 PM ---------- Previous post was at 07:37 PM ----------
That is completely bizzare. The only way that a recovery can be started is via the bootloader. If the bootloader doesn't run, nothing can run. (The recovery is a booted kernel just as with the regular OS). Moreover, you saw the battery screen light up - if a recovery was (still) running, you would think something would show on the screen (although I guess recent versions of TWRP does screen blanking now). Very weird.
Click to expand...
Click to collapse
Can I have the links that you mentioned about users having identical symptoms that "fixed themselves"?
I really don't want to send it in for repairs if it's going to cost me. I'm a student with not much money to spare . One of the reasons I bought the nexus 7 in the first place.
bftb0 said:
By coincidence I was charging mine right now (82%), so I shut it down and looked at that battery animation. (I have the v4.18 bootloader & Dec '12 hardware) First the "lightning bolt" symbol shows up in the battery icon, and the a little later, it performs a "filling the battery up" animation. But here's the important part: when that animation runs on mine, it starts from nearly, but not quite full (mostly white, not all black)- about 82%.
Can't tell exactly from the way you described your situation, but this (again) sounds like your battery is either not charging, or the bq27451 charge controller is reporting the wrong battery state.
Unplug the battery and let it sit for a while before reconnecting. If you have a safe way to measure the battery voltage, do so. You'll know right away if the battery is charged and the charge controller chip is lying.
---------- Post added at 08:14 PM ---------- Previous post was at 07:37 PM ----------
That is completely bizzare. The only way that a recovery can be started is via the bootloader. If the bootloader doesn't run, nothing can run. (The recovery is a booted kernel just as with the regular OS). Moreover, you saw the battery screen light up - if a recovery was (still) running, you would think something would show on the screen (although I guess recent versions of TWRP does screen blanking now). Very weird.
Click to expand...
Click to collapse
I also fully charged the nexus 7 overnight. The battery icon now showed no animation because the battery was full (it first showed a picture of the lighting bolt battery, then a picture of a full battery) so I believe that the battery is working correctly.
patil215 said:
Can I have the links that you mentioned about users having identical symptoms that "fixed themselves"?
I really don't want to send it in for repairs if it's going to cost me. I'm a student with not much money to spare . One of the reasons I bought the nexus 7 in the first place.
Click to expand...
Click to collapse
I didn't make a record of them - you will need to search. What sounded very familiar was when you had said
patil215 said:
...black screen with little white sparks flickering...
Click to expand...
Click to collapse
What I recall - probably imperfectly - was that most of those cases seemed to spontaneously resolve when the owner charged their battery. And since your story started out with "black screen and little white sparks flickering", and "low battery" it sounded quite similar.
The various folks who mentioned this said things like "white lines flashing", "like sparks", or "like snow on an old-fashioned TV screen". Don't know if that will help you search, but they are in this forum (Q&A).
I also don't know if their tablets were in one particular mode or another (judging from a PC connected to the tablet - a black screen on the tab doesn't tell you anything) - I don't think any of them reported this.
As I said previously, that Black and White Google logo is produced by the bootloader. I just started my tablet in APX mode right now, and while the "charging battery" icon shows up when using the APX cold-start sequence (Vol-Up+Power), that B&W Google (text) Logo does not show up on the screen - the tablet goes directly from battery charging to APX mode (detected by looking at the PC - device shows up under "Other devices -> APX" in the device manager; VID/PID pair USB\VID_0955&PID_7330&REV_0103
)
So, my point is that it sure seems like your bootloader is there and capable of at least starting up at least part way.
What if your Vol-Down button was not working and you had a borked "boot" partition? If you had that combination, the bootloader wouldn't go into fastboot mode, as it would never see the Vol-Down keypress... and if your boot partition was borked, then you would never get any boot accompanied by a black screen.
At this point I think you should try observing the behavior of the USB port from the PC while trying to start it up... and even though you've tried it before, see if you can get the fastboot screen to appear. Perhaps there is something funky going on with your Vol-down button.
good luck
bftb0 said:
I didn't make a record of them - you will need to search. What sounded very familiar was when you had said
What I recall - probably imperfectly - was that most of those cases seemed to spontaneously resolve when the owner charged their battery. And since your story started out with "black screen and little white sparks flickering", and "low battery" it sounded quite similar.
The various folks who mentioned this said things like "white lines flashing", "like sparks", or "like snow on an old-fashioned TV screen". Don't know if that will help you search, but they are in this forum (Q&A).
I also don't know if their tablets were in one particular mode or another (judging from a PC connected to the tablet - a black screen on the tab doesn't tell you anything) - I don't think any of them reported this.
As I said previously, that Black and White Google logo is produced by the bootloader. I just started my tablet in APX mode right now, and while the "charging battery" icon shows up when using the APX cold-start sequence (Vol-Up+Power), that B&W Google (text) Logo does not show up on the screen - the tablet goes directly from battery charging to APX mode (detected by looking at the PC - device shows up under "Other devices -> APX" in the device manager; VID/PID pair USB\VID_0955&PID_7330&REV_0103
)
So, my point is that it sure seems like your bootloader is there and capable of at least starting up at least part way.
What if your Vol-Down button was not working and you had a borked "boot" partition? If you had that combination, the bootloader wouldn't go into fastboot mode, as it would never see the Vol-Down keypress... and if your boot partition was borked, then you would never get any boot accompanied by a black screen.
At this point I think you should try observing the behavior of the USB port from the PC while trying to start it up... and even though you've tried it before, see if you can get the fastboot screen to appear. Perhaps there is something funky going on with your Vol-down button.
good luck
Click to expand...
Click to collapse
UPDATE!:
Not sure if this will help at all. But I ran adb -d reboot bootloader, and the device just turned off. Completely. I turned it on again by holding power for 15 seconds but I got the exact same thing as before (google with black screen following). Once the device was on and I connected it to Windows, windows said "Windows detected malfunctioning device". But I couldn't duplicate the results again. Running adb -d reboot bootloader just hangs.
patil215 said:
UPDATE!:
Not sure if this will help at all. But I ran adb -d reboot bootloader, and the device just turned off. Completely. I turned it on again by holding power for 15 seconds but I got the exact same thing as before (google with black screen following). Once the device was on and I connected it to Windows, windows said "Windows detected malfunctioning device". But I couldn't duplicate the results again. Running adb -d reboot bootloader just hangs.
Click to expand...
Click to collapse
Incredibly, extra-ordinarily bizzare. ADB on the tablet side is a daemon process that runs in userspace. You would need a completely functional kernel to be running on the tablet, and a functioning ramdisk too in order to communicate with the tablet. ADB does not talk to fastboot mode, nor any other mode of the bootloader.
IF YOU ARE REALLY SHUTTING YOUR DEVICE OFF AND THEN SOMETIME LATER YOU ARE ABLE TO TALK TO THE TABLET BY USING THE adb COMMAND (not fastboot), THAT MEANS THAT THE BOOTLOADER IS SUCCESSFULLY BOOTING SOME (unknown) LINUX KERNEL.
That truly beggars the question of why you are seeing anything on the screen after the google logo. Did the previous ROM not have a splash-screen?
Well, if you can communicate with ADB it might be appropriate to try:
adb reboot recovery
and see what this does.
If you can find the device in the Windows device manager, what would be really, really helpful would be the device VID/PID pair.
The way you do this is like this:
1) Identify the device in device manager; right-click on it and select "Properties"
2) Select the "Details" tab
3) In the "Property" Combo-box pulldown, select the Property Name"
Hardware Ids
If you can get those values we can identify exactly which mode the device is in. There is a decoder ring at the end of the first post in this thread
OK, I'm starting to get fatigued, as I offer up both things to attempt as well as avenues of exploration, and you seem to simply ignore all of it.
I know you have tried it several times, maybe even a million times. Please try both methods of starting the tablet to try and intercept the initial phase of the bootloader startup and see if you can get the tablet to go into fastboot mode.
It's OK to try it and fail. But in all this back-and-forth, not once have you said, "yes I tried it again and it still failed". Try it and report the result, even if it fails.
Please try it again - both methods. In the second method where you click the Vol-Down button only after you see the B&W "Google" text, you need to do it really quickly - and not let your finger off the Power button either for several seconds.
---------- Post added at 06:08 PM ---------- Previous post was at 06:02 PM ----------
PS
The "-d" option to the adb command should only be needed if you were running an emulator via the Google SDK on the same PC.
If that were the case, when you ran the command
Code:
adb devices[/url]
you would see multiple lines of output indicating multiple devices on the machine - one for each running emulator, and one for the actual hardware device (so long as it is actually booted into a recovery or OS and you have the right drivers installed).
bftb0 said:
Incredibly, extra-ordinarily bizzare. ADB on the tablet side is a daemon process that runs in userspace. You would need a completely functional kernel to be running on the tablet, and a functioning ramdisk too in order to communicate with the tablet. ADB does not talk to fastboot mode, nor any other mode of the bootloader.
IF YOU ARE REALLY SHUTTING YOUR DEVICE OFF AND THEN SOMETIME LATER YOU ARE ABLE TO TALK TO THE TABLET BY USING THE adb COMMAND (not fastboot), THAT MEANS THAT THE BOOTLOADER IS SUCCESSFULLY BOOTING SOME (unknown) LINUX KERNEL.
That truly beggars the question of why you are seeing anything on the screen after the google logo. Did the previous ROM not have a splash-screen?
Well, if you can communicate with ADB it might be appropriate to try:
adb reboot recovery
and see what this does.
If you can find the device in the Windows device manager, what would be really, really helpful would be the device VID/PID pair.
The way you do this is like this:
1) Identify the device in device manager; right-click on it and select "Properties"
2) Select the "Details" tab
3) In the "Property" Combo-box pulldown, select the Property Name"
Hardware Ids
If you can get those values we can identify exactly which mode the device is in. There is a decoder ring at the end of the first post in this thread
OK, I'm starting to get fatigued, as I offer up both things to attempt as well as avenues of exploration, and you seem to simply ignore all of it.
I know you have tried it several times, maybe even a million times. Please try both methods of starting the tablet to try and intercept the initial phase of the bootloader startup and see if you can get the tablet to go into fastboot mode.
It's OK to try it and fail. But in all this back-and-forth, not once have you said, "yes I tried it again and it still failed". Try it and report the result, even if it fails.
Please try it again - both methods. In the second method where you click the Vol-Down button only after you see the B&W "Google" text, you need to do it really quickly - and not let your finger off the Power button either for several seconds.
---------- Post added at 06:08 PM ---------- Previous post was at 06:02 PM ----------
PS
The "-d" option to the adb command should only be needed if you were running an emulator via the Google SDK on the same PC.
If that were the case, when you ran the command
Code:
adb devices[/url]
you would see multiple lines of output indicating multiple devices on the machine - one for each running emulator, and one for the actual hardware device (so long as it is actually booted into a recovery or OS and you have the right drivers installed).[/QUOTE]
Sorry for not indicating the results of all of your suggestions.
Believe me, I have probably tried both of your button combinations at least two dozen times already. And I have gone down every avenue of exploration that you've suggested.
I've even tried every single one of the button combinations in the thread of nexus 7 button combinations. When I do anything from when the device is on, after 5 seconds or so the device turns off. Then the tablet shows the Google screen for about 5 seconds, no matter what I do. After the google screen comes a blank black screen (I can tell the device is still on because it's illuminated black, different from if the device was dead or powered off). There's not even a way I can get the tablet to power off - it just automatically restarts even if it's not connected to power, so I have to let it die or do a battery pull if I want to fix it. The black screen remains there indefinitely (until the battery runs out of course).
I've tried disconnecting the battery, leaving it disconnected for 30 minutes, connecting the device to power with the battery disconnected, having the buttons held down and connecting the tablet to wall power and USB pc, and different chargers. Nothing gives me a different result. The battery is alive and working, and the voltimeter did give me a current, sorry for not posting that earlier. About the random sparks/snow, there is really no pattern to when these appear, although they might be more frequent (but it might just be me) after a battery pull or full battery discharge.
Remember, I used to be able to access the bootloader but that stopped working for some reason. I'm kicking myself right now for not restoring the tablet when I was able to access bootloader, but I was busy at the time.
I've had some experience with rooting, locking, and unlocking other android devices, but this is something extremely weird.
Also, I should have posted the hardware ID's of the device before. I had done the exact same thing as you suggested when I was trying to install an adb driver for the nexus 7 (had to jump through a lot of hoops to get it working on win8, goddamn win8). The hardware ID's are USB\VID_18D1&PID_D001&REV_9999 and USB\Vid_18D1&PID_D001. According to the guide this means the device is in custom recovery, which makes sense because I was running Cyanogenmod 10 with clockworkmod recovery. If normally booting into the OS, the tablet should be giving me the default animated Cyanogenmod splash screen. Perhaps this issue is a bug with clockworkmod recovery?
I know that -d is to target a specific device, however I pulled up adb and went through each command methodically (really tedious) to see which ones would work. For some reason adb -d reboot-bootloader was the only thing that gave me a response, and even that won't do anything anymore (it just hangs, same with any other adb command). adb reboot recovery hangs also, and any fastboot command gives me waiting for device. Since I've installed a driver for it, in device manager the device shows up as Android phone and Android Composite ADB Interface. Windows tells me it's working properly (really? I'm not so sure windows).
I'd like to apologize for not indicating the results of trying your suggestions. Believe me, I have been trying them! I've spent probably a total of 12 hours trying to get this damn tablet fixed.
I'd also like to thank you. Without people like you this forum would not be any good. I am really grateful for any advice even if it does not work.
I know this is a hell of a problem. No goddamn clue how this happened. I love android but I sincerely hope that this is a clockworkmod recovery problem because otherwise that would make it a mistake on Google's (and therefore android's part). I know that the battery issues are quite frequent on android 4.2.2, but I have yet to find another user with my symptoms.
Lastly, do you know of some way to lock the device or destroy evidence of having the bootloader unlocked without being able to access the bootloader, in case this can't be fixed and I have to send it in for repair?
Click to expand...
Click to collapse
patil215,
Whew. That took you some time to write - thanks for all the details.
The USB\VID_18D1&PID_D001 USB Device Id sure does look like the custom recovery. I will assume - unless you say differently - that you would see this VID/PID pair any time you had the "black screen but with the backlight on".
Android uses this thing called the "BCB" (Boot Communications Block) to write instructions for the bootloader about what it should do when it starts up the next time. In the absence of seeing this, no doubt the bootloader has a default behavior. But basically, the way this works is that a "reboot" command eventually causes the kernel to write into this non-volatile memory area, and then a soft hardware reset occurs. The bootloader is aware of the BCB, and under normal circumstances, it will read it and attempt to follow the indicated boot mode - and then either erase the BCB or fill it with the "default booting instructions" just prior to booting a kernel or special-purpose mode previously indicated. In this way it will return to it's default behavior the next time it is booted.
The reason I mention it is that I have seen on other devices that got borked (HTC Droid Eris) in a way that sometimes those phones would always jump into a particular booting mode - and ignore any hard-button presses that would normally cause the bootloader to follow a different path. The Eris had/has "bootloader", "fastboot", and "OEM" modes and sometimes borked devices would not boot into anything other than the OEM mode.
So, since you apparently are seeing some evidence that a partially-functioning recovery is running, that sounds like a very similar scenario - the Asus bootloader is always booting to your (damaged?) recovery.
So, that's materially different (I think) than what other folks might have experienced it. The first time I've seen it here, although TBH I've only been looking in here for a little less than 3 months.
I don't know what else to suggest - it sounds like maybe you've tried things like "adb shell" commands?
If the bootloader can't be forced into fastboot mode, that (possibly damaged) recovery mode is the only privileged thing you have left. It seems to me that if you can't get into that somehow - adb being the most obvious route - then there is little left to do.
No, I don't know how to relock the bootloader without using the bootloader. That's probably something that can only be done with factory methods (possibly in APX mode).
Sorry.
So I was using my N7 as normal last night, starting up Kodi (Previously XBMC) to watch some shows before I went to bed, and as Kodi was starting, my tablet froze. I let it sit there for a good 10 minutes, nothing happened, so I proceeded to hold the power button down to force it to reboot, it turned off, and now it seems to be off forever..
It is showing up in my device manager as APX. I've tried all the tricks of holding down the power button + volume button to get into the bootloader, and it just won't give in. It is rooted, and it's been that way for a long time..
Is there maybe something that I missed in my research? It seems that there are two results; those who can hold down the power and volume and get into bootloader and go from there, and those who never revive the N7.
What are your thoughts?
-Seth
nightfox7 said:
So I was using my N7 as normal last night, starting up Kodi (Previously XBMC) to watch some shows before I went to bed, and as Kodi was starting, my tablet froze. I let it sit there for a good 10 minutes, nothing happened, so I proceeded to hold the power button down to force it to reboot, it turned off, and now it seems to be off forever..
It is showing up in my device manager as APX. I've tried all the tricks of holding down the power button + volume button to get into the bootloader, and it just won't give in. It is rooted, and it's been that way for a long time..
Is there maybe something that I missed in my research? It seems that there are two results; those who can hold down the power and volume and get into bootloader and go from there, and those who never revive the N7.
What are your thoughts?
-Seth
Click to expand...
Click to collapse
try removing the batt then wait for 2 min then put it back then plug it in pc then hold power button atnd up and down button
ngoralph said:
try removing the batt then wait for 2 min then put it back then plug it in pc then hold power button atnd up and down button
Click to expand...
Click to collapse
Tried this multiple times as well..
How did you even remove the battery? We're talking about Nexus 7 aka grouper, right?
nightfox7 said:
Tried this multiple times as well..
Click to expand...
Click to collapse
hmm i think its hardware problem, i also have this problem till now but got it working, but turning off the tablet makes it dead again
hmm for me i just kept repeating the process
---------- Post added at 02:58 PM ---------- Previous post was at 02:57 PM ----------
l33ch0r said:
How did you even remove the battery? We're talking about Nexus 7 aka grouper, right?
Click to expand...
Click to collapse
yes watch some youtube video bout it
l33ch0r said:
How did you even remove the battery? We're talking about Nexus 7 aka grouper, right?
Click to expand...
Click to collapse
It's super easy to pop the back off and unplug the battery.
ngoralph said:
hmm i think its hardware problem, i also have this problem till now but got it working, but turning off the tablet makes it dead again
hmm for me i just kept repeating the process
Click to expand...
Click to collapse
That's what I think as well. I read somewhere that its a CPU failure.
I'll keep on trying, i left it unplugged all night.
nightfox7 said:
So I was using my N7 as normal last night, starting up Kodi (Previously XBMC) to watch some shows before I went to bed, and as Kodi was starting, my tablet froze. I let it sit there for a good 10 minutes, nothing happened, so I proceeded to hold the power button down to force it to reboot, it turned off, and now it seems to be off forever..
It is showing up in my device manager as APX. I've tried all the tricks of holding down the power button + volume button to get into the bootloader, and it just won't give in. It is rooted, and it's been that way for a long time..
Is there maybe something that I missed in my research? It seems that there are two results; those who can hold down the power and volume and get into bootloader and go from there, and those who never revive the N7.
What are your thoughts?
-Seth
Click to expand...
Click to collapse
Mine did this...Stuck at the Google Boot Logo and when I rebooted all i got was APX mode. Unfortunately for me the only way I got it fixed was to buy a Nexus 7 from Ebay with a broken screen for parts. Then I removed the motherboard from the broken one and replaced my bad motherboard with the good one. I tried everything before going this route.
Just an update:
I never was able to revive the old girl. Tried just about everything short of reflowing the board.
I found a logic board on ebay for pretty cheap and dropped it in, it works great and now I have more space! I used to have a 16, now it's a 32.
Also, I put Cyanogenmod on it, and I love it. Much more responsive than it used to be.
-Seth
Another update, she's still going strong, so it wasn't any other failures, only something on the motherboard.
Hey,
This is my first time posting here and really using the site. I have the Sprint Galaxy S4 and just updated to the SlimKat official build 7 and had no initial problems. A day later it starts to reboot constantly and would stay on for a couple minutes. Now it is stuck in a bootloop and will shut off even when going into download or recovery mode. When plugged into a computer the computer won't even recognize the phone and the phone will not turn on. The only time the phone will even start to boot is when it is not plugged into wall/computer and on battery. I have no idea what to do now.
That's a tough one. Usually with a soft brick, if you can make it to recovery, your phone can be saved but since you can't... I hope you get it working!
Sent from my SPH-L720 using XDA Free mobile app
puresublimie said:
Hey,
This is my first time posting here and really using the site. I have the Sprint Galaxy S4 and just updated to the SlimKat official build 7 and had no initial problems. A day later it starts to reboot constantly and would stay on for a couple minutes. Now it is stuck in a bootloop and will shut off even when going into download or recovery mode. When plugged into a computer the computer won't even recognize the phone and the phone will not turn on. The only time the phone will even start to boot is when it is not plugged into wall/computer and on battery. I have no idea what to do now.
Click to expand...
Click to collapse
Go to sprint galaxy s4 thread. All answers there. You need Odin 3.09 then stock ng2 tar. To flash through computer.
Sent from my SPH-L720 using XDA Free mobile app
I already have odin and the tar files for stock. When plugged into my computer it will not even register that it is connected and so I can't use odin to flash it.
The same thing is happening to me. I get to the Galaxy S4 splash screen, then it shuts off. Even if I try to boot into recovery
I'm going to pile on in here as I seem to be having a similar issue. I had my S4 (not rooted, stock rom) on my dock streaming google music. A phone call came in and the phone started vibrating like crazy and wouldn't stop. The screen shut off and the phone was still vibrating. Finally it stopped and was shut off. When I try to start it a few things happens. It will sometimes boot to my lock screen and the screen goes black and I think it is powered off. Sometimes it will get past the lock screen and then die shortly after. After like 2 or 3 times of that it won't even boot. It loads the Samsung screen but never gets to the Sprint screen or boots. If I leave it for some time shut off with battery out it will go back to booting to the lock screen then dying etc... When I press the buttons to get into recovery it says recovery is loading and then the screen goes black. I swapped batteries and that didn't do anything. I tried pressing the menu button or the home button to try and boot safe mode and it just loads normally not that I think that would help anyway.
Any ideas on things I can try next? What is this odin thing? Would that work for me?
---------- Post added at 07:09 PM ---------- Previous post was at 06:16 PM ----------
Ok... I can get into recovery now and will try a factory reset. Are you sure you are going into recovery correctly. Apparently I was not. Hold volume up power and menu button and when the phone vibrates let go of power only.
Before I do a hard wipe is there any way to get data off the internal memory from recovery mode?
So I got a custom recovery installed, reinstalled stock rom, things worked ok for awhile. Then it started random reboots every 10 mins or so. Now it is back to instant crashing and rebooting. Any idea what could be the issue? I'm assuming at this point it is hardware related. Why can recovery and download mode run consistently without crashing but when an os is fired up it has issues? If it was a hardware issue shouldn't it not work across the board?
So I had Sprint replace my phone on the 8th. I have been using my same batteries (1 stock 1 Anker) and chargers (some stock some not) without issue the past 5 days. I rooted and installed xposed and some modules (original broken phone was never rooted and was completely stock). Things were going great until tonight when it started reboot looping exactly like the old phone. I switched battery and same proble. After I took the battery out and left it out awhile it fired back up but I'm afraid the problem will return. Is it possible that the battery or charger randomly are causing damage to the phone? I only have 14 day warranty on this replacement and need to figure this out.
So things were going well for awhile and then the reboot loops started up again. I did some digging and read that apparently Samsung phones are notorious for sticking power buttons and the symptoms were exactly what I was experiencing. I watched some videos online how to open the phone and clean out the power button but it didn't make a difference. I then read that squeezing the connector for the power button with a pair of pliers sometimes does the trick. Not for me. So finally since I'm not under warranty, have no insurance, and the phone wasn't working anyway, I just ripped the white plastic part of the power button right off. Well, that seemed to do the trick. Phone immediately fired back up without issue and has been going strong. I glued a small thin piece of plastic where the old one used to be and I am back in action. If my little plastic piece solution eventually fails or breaks off I will consider soldering on a new button but so far so good.
If you have tried everything else, and are looking for last resort, try cleaning the power button with some alcohol, and if that fails, rip off that power button! Here is the video that gave me the idea: https://www.youtube.com/watch?v=3Glllc7bEJs and here are some other power button videos: https://www.youtube.com/results?search_query=s4%20power%20button&search_type=&aq=f&oq=
I think I'm bricked. My shield is stuck in a simple bootloop and should be considered a softbrick. I can't seem to get into fastboot. Forget adb, that's not responding, but I'm still getting the android boot logo. I've tried so many ways. Holding the button, mashing the bettenbetter, plugging at the brick, power at the console, just about everything. Anyone figure out how to get into fastboot with hardware? If so, please let me know or I'll be throwing this out. It just won't seem to respond to fastboot. Such a shame.
EDIT: Android figured it out somehow and just booted, but I'd still like to know how to get into fastboot for when I'm not so lucky next time. Or any other way to get into recovery.
EDIT 2: Thought I posted this in troubleshooting. My mobile data was lagging somethinf fearce. Sorry.
It can be tricky mate. The way I did it was to unplug the device and then put the power cable back it. As soon as you plug the power cable back in hold the power button down until the fastboot menu appears. It took me a few tries. Of course if you have adb working the easiest way is "adb reboot bootloader"
baileyjr said:
It can be tricky mate. The way I did it was to unplug the device and then put the power cable back it. As soon as you plug the power cable back in hold the power button down until the fastboot menu appears. It took me a few tries. Of course if you have adb working the easiest way is "adb reboot bootloader"
Click to expand...
Click to collapse
I have done it once before, but it didn't work the way that their confusing instructions said. I'll give that a shot though. When android just flat out won't boot enough to access ADB, it can be problematic.
kdb424 said:
I have done it once before, but it didn't work the way that their confusing instructions said. I'll give that a shot though. When android just flat out won't boot enough to access ADB, it can be problematic.
Click to expand...
Click to collapse
It certainly doesn't help that there isn't a physical button on the Sheild, so your not absolutely sure your pressing in the right place after re-inserting the power cable.
In my experience the whole button is sensitive, bit that's still a pain. I have no problems booting my phone to recovery or fastboot, but that's just nuts. Oh well. Hopefully teh learned something as I'm sure their techs are complaining too. It is a consumer device, so I guess I can't be too mad, but still, they expect us to reflash before an RMA when needed sometimes, and that's not fair to ask with thes device lol.
I have the same issue here. I was able to get in fastboot hardware wise a bunch of times before. Now I think the device is done. I've tried every combination. What's weird is I did get a flicker of the bootloader continuing once. What could have changed that the bootloader is not responding anymore? How did you get lucky, let it sit there loading for a day? I've tried to see if fastboot commands can reboot the bootloader when I plug it in timing it correctly. So frustrating.
Yesterday from many many trying times I did it only once and don't wanna go cross again and don't ask me how I don't know how and still don't know how. I did everything by "book/instructions" finally give up and just randomly (panicly ) pressing / holding finger on it, power on / off...and then somehow bootloader screen appear. That should be fix by Nvidia
Sent from my SM-G925K using XDA Free mobile app
---------- Post added at 09:58 AM ---------- Previous post was at 09:49 AM ----------
I hope some developers out there will create some magic solution how enter easily in bootloader mode, like using micro sd ports some modded scripts or usb ports where in plugged in mode console entering bootloader mode or recovery etc.
Sent from my SM-G925K using XDA Free mobile app
Glad I'm not the only one having issues. I've been trying everything with no luck. I'll give it a few more tries and then It's going back. Following Nvidia's instructions is BS. There is obviously an issue going on here that needs to be fixed.
mow4cash said:
Glad I'm not the only one having issues. I've been trying everything with no luck. I'll give it a few more tries and then It's going back. Following Nvidia's instructions is BS. There is obviously an issue going on here that needs to be fixed.
Click to expand...
Click to collapse
It will definately go into fastboot, it's just a matter of timing. It's really tight. In the end I stopped following their directions and just tried a bunch of random stuff. I tried so much I don't know what worked, but doing what they said wasn't working for me.
kdb424 said:
It will definately go into fastboot, it's just a matter of timing. It's really tight. In the end I stopped following their directions and just tried a bunch of random stuff. I tried so much I don't know what worked, but doing what they said wasn't working for me.
Click to expand...
Click to collapse
Same here - finally haotic random pressing / unplugging and at the end done only once
Sent from my SM-G925K using XDA Free mobile app
Im also in the same boat
Just tried to flash stock 2.1 and Full android 2.1 and now the shield wont boot into anything
Im trying the hardware bootloader method but thats not working so far.........ive just unplugged everything, and giving it a while before i keep trying.........i suspect i might have to try rma......that'll be fun...........(im implying, that it wont)
Same here, mine is stuck on on screen and stating production fused , and couple of options like recovery kernel forced recovery, none works fallowed nvidia instructions , tried downloading SDKS And followed commands nothing working , as well tried holding power button , and unplugging and nothing works, I will try what you guys did and see maybe I get lucky somehow
I have a Shield TV power device but the screen is black and I can not go to the Hardw
I have a Shield TV power device but the screen is black and I can not go to the Hardware Bootloader Access:crying::crying::crying:
Same here - when I plug int he power the green light comes on for about half a second then goes off.
Quite infuriating really.
I get a screen that sasys "continue booting..." and then it loads normally do I need to let go once it says this or should I continue to hold?
My screen broke 6 months ago, so it wasn't used/charged for 6 months. Now I've replaced the screen, but it won't start up anymore. First thing I saw was the warning "low battery", so I charged it for a while. Still, nothing. Charged it for several days, nothing. Checked the battery voltage, 3.80 volts, exactly what it should be I think?
The phone does do something though. When I hold the "on" button, after 5 seconds it buzzes and the screen shows the oneplus logo and android. Just for two seconds, then nothing. Same thing with "on" and volume down, the start-up screen for 2 seconds...
When I use "on" and volume up, I get the screen saying "fastboot mode". And that doesn't go away untill I press "on" for a while.
I can connect it to my laptop, but cant see it. But when I take the battery out while connected to the laptop, the phone will show the "low battery" warning. Connect the battery again, and the logo and android message come on for two seconds...nothing more.
So the screen works, the battery is charged, but no way to turn it on. Tried holding the "on" button for 15 seconds, same result. Just a 2 seconds oneplus logo visible...
I have no clue what this could be, I hope its not completely fubar...
Thanks in advance, Fred Doe
Hey Fred Doe,
I wouldn't like to hijack your post, but I seem to have run into the exact same issue here.
A friend of mine got his screen replaced, and the phone acts exactly the same as yours.
I have disassembled the phone and checked all connections, but everything seems to be correct on the inside.
The phone does seem to boot, and it does boot into recovery mode (it responds to the button presses by vibrating) but the screen just doesn't show anything.
Only when doing fastboot the screen stays on.
Hopefully someone here can point us in the right direction.
there's not much to hijack here...sure sounds like the same problem. At this moment I gave up, guess its a lost cause..
Guys, the exactly same thing here. I've tried to unbrick it but failed.... So far what I know is that bootloader is locked.
I would like to know what steps should us do in order unlock bootloader, get screen functioning while getting access back to bootloder (TWRP) so after that we can install a new ROM!
Any clue from the community of OnePlus 2? This phone is still a good phone! Thnx
Have you guys tried running the msm tool. It'll restore everything to stock if you can it to work. If either of you have magisk installed it can cause issues with charging while the phone is off I believe.
I mean honestly sounds more like hardware issue that a msm wouldn't fix, but it's weird that your screen works in fastboot.
If you do the msm tool though be aware it will wipe everything on your device, and relock the bootloader if it is unlocked.
Like I said doubt it will help, but just a thought.
Edit: Also make sure you use the correct one for your device.
Edit sorry guys wrong forum ignore everything I said. Apparently xda labs thought my OP6T was a OP2.
Sent from my ONEPLUS A6013 using XDA Labs
@TheLogicalGamer
no problem. Thnx anyway. I'm still locked with my OP2.
dajosova said:
@TheLogicalGamer
no problem. Thnx anyway. I'm still locked with my OP2.
Click to expand...
Click to collapse
But the screen does show up & stays on in fastboot?
I'm no expert but any stretch. I just jumped ship from lg my 6t is the 1st OP phone I've owned. But if the screen does work normally in fastboot then it wouldn't be illogical to entertain the idea that it was a software issue. So I mean this is a bit of a chin scratcher.
Sent from my ONEPLUS A6013 using XDA Labs
Thanks for replying.
IWhen I press Power + Vol. Up it shoes Fast Boot screen. Then I connect cable and sometimes I can use command line but can't unlock bootloader with command line. All methods found indicate to use Recovery but since my screen doesn't work on Recovery I'm stuck.
When I press Power + Vol. Down (for entering Recovery) screen it goes all black but the capacitive buttons and Volume button give back a vibration response, as if it have entered Recovery Mode but since I can't see nothing on screen I can do anything either.
My bootloader is locked because I see that info via command line.
Thanks anyway
PS: I think something is corrupted. My OP2 was unlocked much time ago. I frquently change ROM's and have also updated TWRP. The only thing I did was disassembling the phone in order to change a shattered screen glass.
I've also tried different methods and installed in my pc different Qualcomm drivers, ADB, etc.
I'm getting close to the point of testing with broken touch, buying a new touch screen but with frame or giving up completely and buy a new phone :|
The last option get me in doubt because I would like a phone wich is good and fast and decent battery but not with a premium price... and popular so I can unlock it without hassle in order to install root apk's.