24" iMac, 3.06 Ghz CPU, 500GB HD, 2GB RAM My imac locked up on me the other day while watching a DVD. There were a few lines and splotches on the screen in various colors and the system just became unresponsive. I rebooted and the system came right back up, but when I started the DVD, it immediately crashed again. After that point, every time I tried to boot, it went straight into kernel panic (You must restart your computer message). I tried resetting the PRAM, but that didn't help. I also did the hardware diagnostic test (hold D during boot) and that said everything was OK. I was able to boot from the CD. After a few unsuccessful attempts at restoring the OS from backup, it finally worked. Previous tries only resulted in the system locking up. Once I finally got everything running again, the system worked great. I worked it pretty hard in the next 24 hours after fixing it. No problems during use. Then I left for a few hours and came back to LOCKED UP COMPUTER AGAIN! Same squiggly lines on the screen. Now I can boot into the hardware diagnostic test if need be. However, I can't boot into the computer any other way. Booting from hard disk, installation dvd/cd, and even Safe mode all cause a kernel panic. Also, I might add, that I had all peripherals unplugged from the machine and still got the kernel panic messages. Any ideas? Closest Applestore is 3 hours away. The closest private licensed repair place is 60 miles away. I called Apple Support and they pretty much blew me off because My AppleCare was up about 6 months ago and I'm sure this would be a hard case to do over the phone. They suggested I take it in to get looked at. I have no problem ordering parts and taking this machine apart and replacing parts. I'm just really looking for a way to diagnose what is actually broken! Thanks!