[One (M7) Q&A, Help & Troubleshooting] vlexster:
Hi all,

last night I started having super weird issues with my M7ul: I found it off, but since I usually use ti a lot, I dismissed it not powering on as dead battery. Later I charged it for a while but it started repeatedly rebooting (just midst the CM12 splashscreen). I found that kinda weird, so I decided to flash a new CM12 nightly build (till that point I was running a build from 23rd or 24th of Jan '15), since I haven't updated it in a while and it had issues from time to time with random rebooting or during calls. I downloaded the latest(20150324) nightly build from the official CM page for m7 and flashed it as I usually do (pack the zip on a USB OTG thumb drive I usually use -> boot into TWRP (up until that point it was 2.7.1.1) -> mount USBOTG -> Install the zip and reboot), but fat chance - the phone started freezing in the middle of the splash screen of the new CM12 anmation (just a fraction of a second before the left year of the mascot gets to normal size). I decided going for one older - but no dice - the old story again. Today me and a bunch of colleagues spend most of the day trying to fix it. For the entire duration of the day we managed it to get only 3 times to an actual android launcher (with cm11 fw I had from a previous update) - the other times it'll freeze, it'll crash, reboot or show the CM animation and then turn the screen black (NOT off!!! - the BL would remain on) and stay like that until one reboots it manually.

We tried a bunch of different things, factory resets, wipes, formats, flashing various ROMs - same thing and hardly any change.

Here're the specs I see:

*** TAMPERED ***

*** UNLOCKED ***

M7_UL PVT SHIP S-ON RH

hboot - 1.54

radio - 4A.17.3250.14 (probably worth noting here, that for the short time it worked today it couldn't find any mobile networks - just wifi)

opendsp - v31.120.274.0617

os - empty

emmc-boot 2GB

some random date in Aug 2013

TWRP 2.7.1.1, initially, then updated through TWRP Manager the first time I managed to get it to boot to the old CM11 (jan 26th) to 2.8.5.0

What else I notice and think is strange is that I'm not able to wipe or mount the /system partition, nor the /devlog. I suppose this might be related to me not being able to properly flash a new rom. What I also find curious is, that I've never had to go through the S-OFF flashing method of going into fastboot and flashing the bootimage additionally. I've tried that through TWRP -> install -> image -> boot image, but doesn't really work. Also I'm not sure whether it's a conflict or not, but having it saying in hboot unlocked and yet s-on is kinda strange for me - I might not be as experienced as most of you guys here, so I think this might be the reason why I find a bunch of these things strange... One last thing I find strange is during wipes and formats I tend to get:

E: couldn't mount: '/system' or E: couldn't mount: '/devlog';

for a while we got also errors about flashing and wiping the data partition, but we finally managed to do get it wiped.

We tried loading the various roms through adb sideload too - same thing; we couldn't get the phone to show up as a fastboot device though. We know of the win 8.1 usb drivers, so we used the win 8.0 drivers instead - exactly the same outcome as before.

Quite frankly after close to 12 hours smashing my head against the wall, I'm about to give up, but decided to give it one last shot asking you guys for any tips we might've missed.

Thanks a bunch in advance!

Cheers,

Vlad

P.S. It's worth noting that:

- I've had issues with this device previously as well - after it installed one nightly build and effectively updating itself from cm11 to cm12, it started having issues with the gapps;

- we fixed the issues with reinstalling the gapps shortly after, but it became extrmely slow

- I had to re-encrypt it (company policy) and ever since TWRP (at that point still 2.7.1.1) couldn't decrypt the storage any longer. I dug a bit and turned out that KK and L had different algorithms for the encryption - the latter seems to use also some HW ID alongside the pass phrase, thus presumably making it a bit more secure.

- I've wiped the storage several times without any success and I was never asked about the encryption passphrase, even last night after started getting the issues and before reflashing it.