I have had the same type of issues as aforementioned. I did all required repairs, new hard drive, installed new RAM, took the LB out, cleaned it all up had the board reballed and installed new ribbon cables. None of these fixes did nothing except to empty my wallet of hard earned $$ !! I put the board back in again, loose, and it fired right up and continued running. GREAT! I added new heatsink compound, replaced all screws and followed the MFR tightening sequence, I pressed the power button with no no avail! So next I started loosening screws, one at a time. Finally after all screws were loosened, it started up. I then started to retighten the screws until I found where it turned off. I then retightened that same screw and it turned back out, the laptop started up again, once the problem area was discovered I found that the by looking closely at the board I could see the board was warped! Now all I have to do is replace the screws with washers between the board and the frame to hold the wrapped board in place and keeping the warp as is, So far it is working like new!