Help - my old P4 took a nose diveelp

So I bought a new computer (q6600, P5Q pro, 8800gt) and was putting my old computer (3.0ghz P4, Asus P5LD2, 7600GT, 1 gig Ram) in my girlfriends office and have been having issues. I am not entirely sure what is going on, so I wanted to run it by you guys to make sure.

I have always had temperature problems with the P4 (getting upwards of 63 C while under moderate load). I never overclocked it, and ran everything at stock voltages. When I put it upstairs, it shut off on me. I pee'd a little and checked BIOS and it said it was 76 C! I thought, this can't be right... it must be a false reading. It had been sitting upstairs for a few days and it had only been on for about 5 minutes. The temp couldn't get that hot. Needless to say, things got worse. Now I can't even get to the BIOS because when I turn it on, it just continually cycles. The only reason I think it might be something other than a crapped out prescot is that the wall plug it is in now is a 2 pronger with an adapter. I was wondering if the problem might be in the power and the temperature is just an anomalous reading. I am willing to buy another old chip to replace it (it will be a word processing internet machine from now on), but I don't want to plug any money in it if it is something else.

Paul

I will give it a shot, but do you think it is too late? I thought I probably fried the chip like a tasty hotwing.

Try different memory if you can.
Could be a power supply going bad.

I have a fairly decent heatsink fan on it (better than the original heat sink). I just tried reapplying thermal grease and reseating it but it didn't help. It comes up with the ASUS screen and then goes black and does it again until I get depressed.

The power supply is a generic 450 watt that came with the case (Xion) - It was my first build and I didn't know better. Is there a way to test the PSU?

I will try plugging in some memory to see if that is it.

Thanks for the help!

I tried reseating everything and turning it on again (I thought I was onto something because my SATA cable has always been loose). But it didn't work. I think I should probably just try getting a new chip for it and give it a shot. They aren't too expensive at the egg. What heat sink should I get for it?

OK... this is becoming a lot like that movie with Atreyu and Falcor. Sorry, I like obscure movie references ("BE CONFIDENT!" )

So I THOUGHT it was fixed because it turned on and worked normally for the next 4-5 bootups. Now it is doing it again. Same symptoms as before. Is this indicative of a power supply? It wouldn't surprise me since it is a XION generic PSU.

As for the CPU fan, that was a big my bad. I didn't have my glasses on when I was plugging things back in and I accidentally put it into the Chassis Fan slot.

I am close to just buying a cheap mobo/cpu and new PSU and be done with the problems.

Anyway, any help I can get so my girlfriend doesn't have to use my good computer to play mahjong for 6 hour marathons would be very appreciated.