Ok, kindof a weird problem here. Equipment is:
VGA Radeon 9700
Built in 2002
Never had a problem with heat until we moved the computers into a small room. then there were display issues that cropped up (see pic. it's rather worse than usual, but that's what sometimes happens). In 3D games, polygons freak out and it looks like a disco show. I've seen this in laptops with inadequate video processing power.
I the video card was getting insanely hot, so I got a Kingwin Heatsink, looks like a giant blue sandwich with three extra fans on it. That worked for a while, then when the room gets hot it starts happening again. Sometimes just when I turn on a game, sometimes just viewing the desktop.
So I replaced the cooling compound with an Arctic Silver ripoff (couldn't find the name-brand locally) on the cpu, and the components of the vga heatsink.
Feeling the heatsinks doesn't seem hot, there is some warmth near where the vga card meets the motherboard, but nothing much.
Things I'm thinking about but just wanted clarification:
Stock PSU > just recently noticed the fan on the bottom of it is not spinning. Looks like some dust may have clogged that up, or it may have overworked itself. Intel Active Monitor states my temps as CPU: 30c, and two system zones at 29c. Not bad, as before the Silver compound and the heatsink they were in the 50's.
Replacement cpu Heatsink/Fan > fan spins easily and smoothly. I can blow on it while it's off and it will keep spinning without hitch. Until the overheating happened, the stock heatsink (rather large) has been fine. Dusted it a month ago.
Pic of my desktop when it's freaking out: Image
I appreciate any time taken looking at this problem, I'm going to gut out the pc and clean all components and re-silver heatsinks. I'd prefer not to spend too much on new hardware because of the new technology out. Thanks for looking =)