I have a Nexus 6p that is unlocked and rooted. Last night it restarted unprompted (this has happened a few times since Nougat) and it no longer boots into the OS. I get the initial warning about the unlocked bootloader, the white Google logo with the unlock icon, and then it just keeps on rebooting. I powered it off last night and let it rest but that didn't help.
This morning I downloaded the 7.0.0 (NBD90X, Oct 2016) angler image. I tried flashing boot, cache, recovery, and system manually with fastboot and it was still in a boot loop after restarting. I ran flash-all.bat and that didn't help either. I'm not sure what to try next.
Update: I found the hidden menu in recovery mode (hold power+volume up in the recovery menu). Then was having difficulties getting ADB to recognize the phone when I noticed there was a different ADB version running in the background by Droid Explorer. I got that sorted out and uninstalled when I still couldn't get ADB to see the phone when some combination of uninstalling/reinstalling the USB drivers from google and trying different usb ports finally was able to list a device when running adb devices.
So after running wipe cache partition and running apply update from ADB with the latest OTA update (bootloop), and the latest Marshmallow update (Warning: Nofile_contextThis package is for "angler" devices; this is a "".), I'm still stuck.
Update #2: well since I haven't had any luck with anything so far, I tried doing a factory reset with hardware buttons in the recovery menu. Still boot loops. Are there any other options or should I ship it off to Huawei?
Final Update: since no other options worked I contacted Google Fi and they are sending me a replacement phone. Even though I am a few days beyond the warranty's expiration they are sending it free. (I also contacted Huawei and they comically sent me an email telling me to call their support's phone number.)