Hi, I have been doing a ton of research on overheating, and still cannot figure out what is going on with my stupid computer. About a year ago (when it was about a year and change old; just out of warranty) my computer started acting up. It would shut down unexpectedly and the power light would flash yellow. I found that if I took the side panel off the case it would work better. Eventually that fix stopped working and I installed a new hard drive as I could hear the hard drive start up and never stop reading when I started the PC. I don't know what that problem was (virus or excessive heat) but once I installed the new HD everything went back to normal (case back togeather and normal fans).
Everything was good until about two months ago when it started shutting down again. I hard another Hard drive laying around and installed and started putting a fresh copy of windows on it when it shut down again. I bought a new power supply thinking maybe that was the problem, I upgraded from a 220w compaq supply to a 350w raidmax. The problems continued. I changed all the fans (the only ones factory installed were the cpu and a rear exhaust fan) with new thermaltake fans. problems continued.
It would only stay on for five minutes or less at this point, no matter what I did, if I was in the bios screen or a blue windows installation screen. I did some research and decided to take the heatsink off and apply thermal grease to the processor die. I used a razor to scrape off the factory installed thermal pad from the die and the heatsink and applied artic silver 5 thermal compund. I started it up and it shut down after about three minutes; when I restarted it, it seemed to be better. The computer stayed on for about three weeks after this fix, we manually shut it down maybe three times during this period and it all seemed to be fine. But it started shutting down randomly again. I scraped, cleaned with alcohol, and and reapplied the arctic silver 4 times, using different amounts. I took the side off the case and drilled a bunch of holes and mounted an intake fan pretty much in line with the processor. air flow in the case is much improved. But the thing still shuts down abruptly after about five minutes and will not restart until it has cooled.
Immediately after shutdown I took the side panel off and checked the heatsink temp with my hand, slightly warm to the touch, but nowhere near 80 or 90 degrees celsius. I have tried to install MBM to see what the temperature sensors are doing but the computer won't stay on long enough for me to get through it. The only thing I can think of, is that I have a bad temperature sensor(s) that is blocked or for some reason is reading unusually high. To my understanding there is a sensor in the processor itself and also one or two on the motherboard somewhere.
Do I need a new chip or a new motherboard, or both? Or is there anything else I can try with the stuff I have? I have two other computers in the house that are running wonderfully, but the printer is hooked up to this family computer in the livingroom, and it just won't stay on. Please help! I am at my wits end!