Hello fellow Macheads. I've got an issue with my white 13" macbook core2duo. After a while, maybe 30mins or so, the screen goes blank. The machine is still on, but quieter than normal. The battery is not the problem, also removed it just in case it was shorting the machine and ran it from the mains charger, same problem. I reinstalled Leopard, but it didnt install in time. I tried a brand new hard drive, made sure it was formatted, partitioned etc, same problem. Sounds like it might be the motherboard, possibly the fan on the cpu as it does go very quiet when the screen goes blank. Its an odd one, anyone have any ideas?