[Q] Phone hangs during use - sometimes fails to mount /system or /data
This has been ongoing for a few weeks now. Desire S is currently running Endymion 2.2, but the same thing happened on Cyanogen and Stock roms. Phone will work fine for up to a day, then will completely freeze up during use (has happened in Browser, while entering text, and once just on the lockscreen). During the hang the touchscreen won't respond, connecting USB has no effect (no LED and ADB Devices lists nothing), the 4 buttons give haptic feedback for about 5 seconds after the hang, then nothing. Holding volume+power has no effect, but usually after about 10-20 tries or 15 minutes of doing nothing the phone will return to HTC boot screen, and sit there until I power it off and then remove the battery.
When using clockworkmod, half the time either /system or /data is not mountable (this only happoccasionally get "error mounting /cache/recovery/log"). When this is the case, formatting/factoryreset sometimes gives the "can't mount /data" error, and sometimes works.
Since switching to 4EXT the partitions are always mountable from recovery, but rebooting causes the phone to hang immediately after booting.
Current setup (which at the moment is hanging at the lockscreen)
4EXT Recovery v2.2.7 RC5 (/system /cache and /data all ext4)
tldr: is it possible for /system or /data to break during normal use and sometimes be unmountable? If yes, then can this be prevented? If no, any other suggestions as to what could be going on?