Originally Posted by econometrician
This is my own experience, but I want to warn you guys. I had a similar problem with my GNex. The first time it happened, my phone rebooted itself every 5 seconds. I completely restored it using factory image and it ran fine for 3 weeks, then one day, the phone just rebooted itself and got stuck at the boot image. I had to factory reset it again to make it work.
After the second time, I called Samsung and sent it in for repair last week. They are shipping me a replacement unit. It seems the problem was hardware related.
For 3 weeks... exactly 3 weeks, 21 days?
I can tell you that my first boot loop brick was 20 days after I bought the phone. The second was later that day. But the third one was... again, 20 days after the last successful restore. Is there something magical about the 3-week mark???
I am currently taking nightly nandroid backups, so when I had my third boot loop brick my backup was just under a day old. If this is ultimately a hardware problem that can be warrantied, I guess I'll have to try that next time. I would have to make sure I return it with the bootloader locked, stock recovery, but without the wipe because it has to still be boot looping to prove there's an issue!
Anyway, things I will point out:
- It's the complete wipe in bootloader that blanks the internal storage.
- If you have CWM installed, you can back up the internal storage over USB via adb pull /sdcard/ ./sdcard/
(correct me if I got the syntax wrong)
- When the boot loop brick has happened, CWM is not capable of properly reformatting or restoring to the data partition. I have not found a way to repair it without blanking /sdcard (which on the GN is actually in /data/media), so if you don't want to lose those files the only way to keep them is to pipe them out, blank the phone, and then pipe them back in afterwards.
- After a complete wipe in bootloader (either by flashing userdata.img or by relocking/unlocking bootloader), you must boot the phone once into the OS in order to complete the reformatting of /data. If you try booting straight into recovery after a wipe in the bootloader, CWM cannot read or write from that partition.