Random computer lockups after replacing thermal paste

[helppls]

1 week ago, I dusted my computer with a can of air and took out the processor/hsf to apply new thermal paste. This was after I saw my cpu temps were in the 90s with load.

Ever since then, it locks up at semi-random intervals. It generally locks up before Windows even begins to boot (on the mobo loading screen), requiring 2-3 resets on average to get into Windows.

Once in Windows, it locks up after a 1-4 hours of operation. The screen just gets frozen, requiring a hard-reboot.

It runs through prime95 flawlessly, memtest86 4.2 passed no problems. Max temp is 66 under load according to RealTemp.

specs:
core 2 duo e8400 at stock 3ghz (never oc'd) with stock hsf
2x 2gb ram
micro-atx asus mobo g31 chipset (model P5KPL-CM)
ati 4850

 

[Puppies04]

Check all mobo/psu connections, I know you think this is "random" but it isn't. Something has changed and as it occured right after you were working inside the case chances are you knocked something. Reseat the CPU aswell.

 

[helppls]

Check all mobo/psu connections, I know you think this is "random" but it isn't. Something has changed and as it occured right after you were working inside the case chances are you knocked something. Reseat the CPU aswell.

I checked the connections, blew some air in them and reseated the CPU. Threw in a new hsf for good measure.

No problems since.

Thanks!

 

[Bacinator]

If you were using a newer CPU which 'sits' on the socket pins, instead of having pins that insert into the socket, it's possible the pins were not making proper connection with the CPU.

A symptom to look for (should it happen again) is how much memory is being reported. This problem also seems to prevent all memory banks from being recognized and will show only a fraction of installed memory on boot or in system properties.