A few days ago, my computer randomly shut down while importing a 30 minute video into a video editor. After rebooting, I opened up Speccy to see if it was a heat issue, and as I suspected it was. The idle temp for the CPU is around 40C. That's pretty normal, but upon re-opening the editor, and trying to import again, it skyrocketed to the upper 70s. This is dangerously hot, as it prompted the computer to shut down again. I've been editing videos for a while, and this didn't start happening till a few days ago. I was recording another video today, of me showing some stuff in Sketch Up, and it shut down again. I've done some tests, and drew a ton of polygons in SU to see if it would get hot. It didn't. Probably cause SU is handled by the GPU, I'd think. It seems to only heat up when doing things that require a lot of CPU power.
What I think it is:
I think that A) My CPU is dying (it's 6 years old, and has been used heavily), or B) It's the motherboard that is dying (same age). I think it could be the mobo cause the heat sinks on the north and south bridges were very hot to the touch, and my Speccy shows the mobo idling at around 41 after it was rebooted. The hard drive temp is fine, and it doesn't show the GPU temp for some reason. If it is either of these two components, it might be some time before I'm able to work on anything, as I don't exactly have 600$ lying around for a new CPU/ mobo. I do have another, significantly weaker computer I could use, but.. that's no fun.
What I've done about it:
I took apart the case completely, and cleaned it out again. The disheartening part that makes me think it's age based hardware failure was that the inside of the case was actually pretty clean. Cleaner than it was a few months back when I was having similar heating issue, but a new heat sink, and some extra fans seemed to fix it then.. but this is now. I think it is worsening. I also reapplied thermal paste, but the paste that was on there was still pliable, and not dry at all. All of this didn't seem to do anything. It still gets really hot under load, and it shuts off at around 78/80C.
So I'm thinking this is it.