How to fix a Nexus 9 that bootloops after an official update? Summary


Nexus 9
Never rooted the device and boot loader is locked
Stuck in a boot loop since an android update
Factory Reset doesn't work
Recovery mode doesn't work
Can't flash anything
Can't unlock boot loader due to OEM setting
OEM setting can't be turned on due to boot loop


Context

I bought nexus 9 and I have never rooted this tablet or have done anything fishy to it.

Within few months I received a new android update and I got stuck in a boot loop with a message "Your device is corrupt..." and I lost access to my precious non backed up pictures.
However, I have abandoned the pics and decided to try factory reset.
I get stuck with a green android icon when I try to factory reset for about half an hour then it reboots, but it still gets stuck in boot loop.

So then I try to start the recovery mode but then I get stuck with a dead green android icon with red warning sign.

So what do I do next? I try to flash a custom recovery program, TWRP.img using fastboot but I can't because the bootloader device status is locked.

So I try to flush all preinstalled img to stock, so I try unlocking boot loader using fastboot oem unlock but I can't because I didn't turn on the OEM permission on before being bricked. If only there were way to turn on OEM from adb but I see a lot of people saying its not possible.

How can I fix my tablet?
You should still be able to sideload an official OTA update from the stock recovery. You can get the official OTA images here: https://developers.google.com/android/ota


Download the latest OTA image for the Nexus 9 from that page
Reboot into recovery mode
Press the volume up and power keys at the same time to activate the hidden menu
With the volume keys, highlight “apply update from ADB” and press the power button to choose it
From your computer, execute adb sideload otaFilename.zip