I have the same model, A1150 with all the same hardware. Also running the same software - 10.6.8 Have the same problem. Seems to come and go. I discovered if I open it in firewire mode, and let it heat up, it seems to clear and work again. Eventually it will begin to get red lines on the screen and then freeze up. Tried to access it via shared screen but no response.
Anybody have any thoughts on what might cause this problem???
Thanks for the response. I did more searching on the net and read several accounts of people with similar problems. The all seem to agree that it is the ATI Radeon X1600 GPU (yes, it does show up on mirror mode). They all seem to implicate the heat from the unit and heat transfer. I pulled the logic board cleaned the dirt and dust and cleaned the transfer goo from the 3 processors. I also put a hair dryer to the 1600 for about 10 minutes (with an aluminum foil protection for the rest of the board) added new goo and reassembled. (See Youtube video) It seems to be working just fine now.
Some odd things I have noticed...
It seems to actually work better when it is warm or hot. It gets the lines and tire tracks when it is waking from sleep or when it is still warming up. I have also discovered that if I force it to restart and then hit the T key it will go into firewire mode. After 10-15 seconds in firewire mode the screen clears and I can start it up with no lines. Very strange behavior.
Anybody else ever tried firewire mode to clear the problem? It worked for me every time.