Hello group, I need your help & WISDOM. I built my own computer - Antec case, Gigabyte GA7N400 motherboard, AMD Athlon XP 2400 processor, 1gig ram, ATI All-in-wonder AGP card, Sony DVD player, Sony DVD burner, 3 hard drives, Windows XP Home SP2. It was working great, then I decided to install a rear cooling fan in the case. I had an 80mm fan with a heat sensor lead on it for variable speed, connected to a power lead from the power supply. Somehow I pinched the sensor lead and when I tried to restart the computer, it would not start. So I opened the case, found the problem, repaired the sensor lead, and restarted the computer. Worked ok. Then my monitor started to go black intermittently. So I tried another monitor, worked ok, then it started going black. Opened up the case and found the cooling fan for the CPU was not working. So I changed the CPU Cooling fan. Still didn't work. Re-installed the original cooling fan, and hooked up the fan to a power lead rather than hooking it back onto the motherboard. Fan worked ok. but system still UNSTABLE. Now the QUESTION - do you believe I fried the CPU (?), the motherboard (?), both (?) or do you have any other ideas? Any help would be appreciated.find another compatible processor and switch it with your own.

then come back and report the results.Since you "Opened up the case and found the cooling fan for the CPU was not working", I believe you may have fried the CPU. Based on numerous comments I've seen in forums on AMD CPUs and their vulnerability to rapid damage in case of CPU fan failure, I understand they can be ruined within seconds of operating without a fan.

Do you have any idea why the CPU stopped working? It had prviously been working, right?No, I don't know why the CPU fan quit working, but the CPU was still working, the machine would just go blank, sometimes reset itself. So I don't know if the Power Supply was damaged when I shorted the case fan sensor leads, or if that took out something on the motherboard. I also have READ of AMD processors being "fried" if you don't have a heatsink on them, but my heatsink was still on the CPU, with the CPU cooling fan not working.AMD processors will fry within a second or two if the cooling fails. Intels have thermal protection so the machine will turn off to protect it.OK, but does the CPU control the CPU cooling fan operation? Did I also fry the motherboard? And/or did I damage the power supply? Thanks for the help.You'll have to replace it a piece at a time until you see what it takes to get it going.Quote

OK, but does the CPU control the CPU cooling fan operation? Did I also fry the motherboard? And/or did I damage the power supply? Thanks for the help.