Okay, so one day my computer tells me upon startup pre-boot, "CPU fan has failed, shutting down to avoid damage blah blah blah". The computer starts after a few tries. I check the CPU fan upon one particular failed startup. It's twitching like it wants to go somewhere but it won't start spinning unless I give it a few supporting turns. So I go and buy a new heatsink/fan, and the same thing happens. SpeedFan reads that my 3rd fan (which I'm assuming is the heatsink-mounted one) is running at 0 RPM, even though it's spinning when I check. SpeedFan ALSO tells me my core is burning up at 60C. What exactly could be the issue here?

My computer is an HP Pavilion a3660f.

Do you know what motherboard that is? I can't find any information on a3660f(it's like it doesn't exist). You could try re-setting the bios. To do this, turn your computer off, unplug it, take the battery off of the motherboard, wait 5 minutes, then put it back in. If that doesn't work I would flash the bios.

http://www.hp.com/hpinfo/newsroom/pr.../ds_a6330f.pdf

Not sure what motherboard it is, but I'm computer illiterate.

Do you mean the button battery that's located directly on the motherboard?

Oh, you had the 6/3's messd up.

Yes. I hope that does the trick.

My bad.

Well, let's find out.

I can't see any info on the HP site about flashing the bios, or what motherboard it is

Didn't work.

Question...what would happen if I plugged the CPU fan into the slot for the case fan, and vice versa?

What can I do to find out what motherboard it is?