Today I tried jailbreaking my iPhone 3G running 3.1.3 using redsn0w 0.9.4, which was working like a charm up until the reboot in which case the phone had a permanent white screen of death. I've tried everything, hard reset, DFU mode, even restoring it through iTunes and re-jailbreaking it. It restores just fine but still has a permanent white screen that I can't get rid of. The phone has never been dropped and was working perfectly up until the point I tried to jailbreak it with redsn0w. Any ideas?
White screen isn't good at all. Seems like something hardware got damaged, not likely a software problem.
Set it into Recovery Mode (not DFU, it's different) and do a restore to stock 3.1.3. See if the screen clears up. If it doesn't, it likely needs a new LCD.