It's the popular GPU Problem of the Nvidia graphic card.
Somehow the lead between the BGA chip and board breaks and the result is not boot up with a black or white screen; or artifacts in the internal and external display...
Possibilities:
- Buy a new one and throw away the old one
- Try to ask apple for a "free repair" -> good luck
- Reflow with hot air gun/oven/Prof. Reflow station
- Reballing
- Bring it to somebody who can fix it...
I decided to try the hot air gun method...
I made it twice already before, but I think not good enough...
So I did some research and did it for the third time.
This time I recorded it:
Detailed information about the different methods I tried:
First time
Method: Used a cheap (borrowed) hot air gun and put it on top for about one minuteDurability: 1 month
Second time
Method: Used a much better hot air gun (with digital display & +/-10°C interval) 240°C on top for 2 minutesDurability: 2 months
Third time
Method: Used a thermocouple to messure the board temparature on the top of the board, heat up the bottom to aprox. 110°C, Heat up the top up to aprox. 220-230°CDurability: Don't know yet... hope a life long... ;P