The laptop starts off okay, then stays on and works properly for about an hour or two, but i remember that it did stay on for about 5 hours once after it developed this shutdown problem.
I thought it was overheating first so I dismantled it , reapplied thermal paste to the top of the processor chip, then closed it back up. But the problem didnt go away. Oh I cleaned out the fan and the vent system at the same time. There wasnt too much dirt though.
Anyways, next I thought there might be a virus so I backed up everything and reinstalled windows 7, but still the problem didnt go away.
What else can I do?
I have another thought though. The GPU chip or the chip that is also under the heat exchanger pipe has a kind of spongy material on top of it, which I assume is also some kind of thermal conductor. I did not take out that spongy material and it didnt look like it had worn out either. But is it possible that if the GPU overheats, then that can also cause the computer to shut down?