Three weeks ago, I disassembled my notebook to clean its heat sink. I re-applied thermal paste and re-assembled it. It worked well, until about three weeks when it hard shut down while I was working with it. When I tried to turn it on again, it only got as far as the desktop before shutting off. After a day, the power button did nothing at all.
Service said that there was a problem with the video card being unsoldered and soldered a new one in, but it has stopped booting again. Now I think that I may have applied applied more thermal compound than usual and that it somehow damaged my CPU or video card.
What did I do wrong?