For the past 3 weeks or so my GS3 has been randomly rebooting. It's happening about 3 times per day and at varying times - sometimes when I disconnect from the car charger, sometimes when a call comes in, sometimes when it's sitting on the desk.
I'm rooted, unlocked bootloader running CleanROM 8 (Android 4.3).
Any thoughts on why this started now?
The CleanROM thread was closed, Scott gave up getting 4.4.2 to work without locking the bootloader. The thread is still there, with several postings by people with reboots. I think that the main question that's asked when that happens is whether a clean or dirty flash was done. That is, was a wipe done in recovery mode before flashing, or not. If not, this is a "dirty" flash, and some problems may come up. You can always try a wipe and re-flash CleanROM, that's most likely the first thing that I'd try, dirty or clean initial install.
I was on CleanROM 8.2 when Scott closed the thread, had no reboots. Decided to use odin to install 4.4.2 over it and then root with towelroot. Doing okay, killed lots of bloat using Titanium Backup. Since I only have 3 months until I can upgrade, I'll live. But no more Samsung for me *smile*, Knox was really a bummer, don't need it.
Here's the closed thread, if you want to search it and look for information about reboots:
[ROM][6/7/14] - CleanROM 8.2 -★| Clean! | Smooth! | Stable! | No Gimmicks! |★- - XDA Forum
Update: There is a new CleanROM support thread in xda-developers forum that you might also use. It's just started, so nothing much there yet, but there is interest. One of the guys that helped Scott a lot with support is helping out there:
CleanROM 8.2 tech support