|Ways to check might include starting in bios and watching temps if they report there. Also look there for temps shutdown and warn numbers. Compare them or enable them at least to warn.|
Apps can also be installed to monitor temps on motherboard and maybe the video card.
Might look at event logs or dump logs. Watch for services that fail. Might go to services are change how they restart.
I'd consider running a live cd too to see if it might be software/driver related.
Might have a cold solder joint on the motherboard that is now found because of moving parts around.
Could try to reseat all components.
Why did it take me over a year to phone in a problem to ATT?