I have saved ( thought so) a water damaged macbook pro late 2011. After cleaning the board and re-applying thermal paste it seemed to work fine. heavy load on both the gpu's and cpu didn't give any problems and the temps stayed wel within the "good" values. But when i reboot it it goes dark.. startup gives me the optical drive sound, then chime and the only black screen. after a while the keyboards lits up.. So it seems it starts up but no video. i've tried all the smc and nvram tricks to no avail. What is most annoying is that after a night of rest it has no problem doing heavy work.. but i cant reboot it because then i would need to wait another night. Is it possible it needs to rest to lose static electricity? I have thought about a little reflow operation of the gpu's but don't expect much of it because of the fact it has no problems "when" it runs. Hope someone can help me discover what the problem is, and if any symptoms are familiar with maybe the gpu's gone bad..