Hey,

when I'm starting my MBP I get about 10-60 seconds of the booting process before the screen goes half black (Its like applying a black to transparent gradient from the left side of the screen to the middle of the screen). After a 5 seconds the entire screen blacks out and the MBP shuts down.

There have been issues with heat and some minor artifacts on the screen in the past but nothing serious as far as I know. Everything could be resolved by rebooting or letting the MBP cool down a bit.

I would like to identify the problem now. There are 3 possibilities I can think of right now:

1. My graphics card is defect and shuts down after a few seconds. (But if thats true, I find it kind of hard to explain the HALF black screen)

2. My LCD-Panel is defect and sends back wrong signals so the system shuts down??? (I not sure about that)

3. My fan or/and thermal sensors are defect and forcing the graphics card to shut down.

Can anyone point if I'm right or if there yet another reason for this.

I'd be thankful for any hint or tips.

Cheers, Per