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[Q] Nexus 7 Not booting (Flashes google screen (2-3sec) and then black screen)

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matthewobrn
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Default [Q] Nexus 7 Not booting (Flashes google screen (2-3sec) and then black screen)

Hi,

So my missus dropped her tablet (again) and this time she managed to smash the digitzer. So I went to replace it along with a new screen...
6 months later I get around to changing the parts. I reassemble and try to fire it up.

The Google logo flashes up and stay for about 2-3 sec and the disappears. Then nothing happens.
I tried plugging it in for 10 hrs and retried. No luck.
I can boot into the boot loader and the buttons work.

When I "power off" the device, suprise, it shuts down, on power up the logo flashes again and nothing.
Next I try "start" logo flash and nothing
When I tried Recovery the same again, then after about 60 sec it flashed the funny colored Nexus logo (very quick flash) then nothing again
When I select "Reboot Bootloader" it restarts the boot loader.

I'v been crawling the internet for hours now and have only found repeated attempts of loading the bootloader and trying recovery mode.

I did connect the tablet to the pc for a minute and could see a file structure but haven't been able to do that again.

Can someone please help.

Thanks
Matt
 
matthewobrn
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I'm beginning to think that the memory with the os has been lost, I might try unlocking the boatloader and refreshing the oem Rom. Any thoughts?

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matthewobrn
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So I unlocked the bootloader and flashed the newest stock rom to the tablet and still wont boot.
Same as before, Google flashes up and then black screen.
 
matthewobrn
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So, I figured it out. It was working the whole time, only the backlight went off after the Google logo disappeared. Its not the brightness sensor as its reading correctly in GPS status. It seams to be a software issue.

I've set the brightness to a fixed level and it is working OK, when I set it back to auto adjust it turns the backlight off again, when I shine a torch on the sensor I goes bright again.

Sent from my Nexus 7 using Tapatalk
 
ghanchi
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Quote:
Originally Posted by matthewobrn View Post
So, I figured it out. It was working the whole time, only the backlight went off after the Google logo disappeared. Its not the brightness sensor as its reading correctly in GPS status. It seams to be a software issue.

I've set the brightness to a fixed level and it is working OK, when I set it back to auto adjust it turns the backlight off again, when I shine a torch on the sensor I goes bright again.

Sent from my Nexus 7 using Tapatalk

I am having the same problem as you have described above. After changing the digitizer/ lcd, the tablet boots up and google logo shows up for few seconds and the screen goes blank. It goes into recovery fine. How did you fix it?
 
matthewobrn
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Turns out it's the lux sensor. Turn it on wait for the Google logo to disappear and grab a bright torch and hold it over the lux sensor it's right beside the camera the screen should go bright once it gets to the lock screen. If not use the torch to see what's on the display and once you've unlocked the tablet set the brightness to constantly on full instead of automatic brightness and this will override the lux sensor.

Sent from my Nexus 7 using Tapatalk
The Following User Says Thank You to matthewobrn For This Useful Post: [ Click to Expand ]
 
ghanchi
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Quote:
Originally Posted by matthewobrn View Post
Turns out it's the lux sensor. Turn it on wait for the Google logo to disappear and grab a bright torch and hold it over the lux sensor it's right beside the camera the screen should go bright once it gets to the lock screen. If not use the torch to see what's on the display and once you've unlocked the tablet set the brightness to constantly on full instead of automatic brightness and this will override the lux sensor.

Sent from my Nexus 7 using Tapatalk
Thank you so much. I followed your suggestions and now Nexus 7 is back up and running.
But I am afraid of rebooting it because I wasn't able to replicate your instructions once I had to reboot for system update. I had to flash factory image through fastboot and had to redo the initial setup and then the screen turned on welcome screen. So, it is hit and miss. Sometimes screen does turn on after few minutes of booting and sometimes it takes several hours for the screen to turn on.
I have my screen brightness setup to full. Will this override the lux sensor permanently or only until the next reboot? What is your experience with the tablet since you discovered this solution? Again, thank you so much for your help. I almost gave up on it and was ready to trash it.
 
matthewobrn
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Setting it to full with auto off should kick in after boot. When mine boots up it doesn't show the swirling dots but once it's done loading it pops up with the lock screen. I read somewhere that YouTube overrides the brightness setting and defaults back to using the lux sensor. I downloaded and paid for lux auto brightness that can override all app brightness settings permanently and it worked a charm for me. Maybe give to lite version a go and see how you get on.

Sent from my Nexus 7 using Tapatalk
 
ghanchi
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Quote:
Originally Posted by matthewobrn View Post
Setting it to full with auto off should kick in after boot. When mine boots up it doesn't show the swirling dots but once it's done loading it pops up with the lock screen. I read somewhere that YouTube overrides the brightness setting and defaults back to using the lux sensor. I downloaded and paid for lux auto brightness that can override all app brightness settings permanently and it worked a charm for me. Maybe give to lite version a go and see how you get on.

Sent from my Nexus 7 using Tapatalk
Thanks, just downloaded Lux Auto Brightness. Will see how it goes.

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