Ok, the earlier part of my iMac's problem can be found on this thread: http://forums.macrumors.com/showthread.php?t=212747&highlight=frozen+iMac Long story short, my iMac needed a new motherboard, which the folks at the Apple store installed for me. Ok while we're at the Apple store testing out the repaired iMac these gray lines came across the screen (never happened before) by the time we called some one over they were gone. We explained to the associate what happened but he didn't seem to believe us. He restarted it again, it worked fine and then we were told it was ready to be brought home. I set it up on my desk and the first time I turn it on, the entire screen is covered in grey lines and the computer doesn't turn on. I restarted it and it happened eight times. Finally the maching booted up, however it only went a few minutes before it froze. I called the Apple Store again and I talked to the employee who installed the motherboard and he said to try a PMU reset, which I did and the computer seemed to be working fine during the night. Then this morning I turned the iMac on again and the gray lines came back, but it booted up. However the image on the display became all choppy and distorted (kernel panic??) and the machine froze. I tried another PMU reset and rebooted the machine several times and it still freezes. Apple just replaced the motherboard (which took a week) what do I do now? I've called the Apple Store three times already and they're not being very helpful (actually they're being a bit snippy at me) The computer is still under one year warranty, however it's the iMac G5 with isight (so I doubt they'll take a return on it cause it's an older model). In short the workers at Apple have basically told me they don't know what's going on. What should I do? ask for a refund/replacement? We've already wasted lots of time and money on the iMac's repair. Should I bring the pictures I took of the screen with me into the store and show them? Any help is appreciated, I need to know what to tell the Apple Store employees.