Hi, I have a homemade computer for my son's to play games on. My son was playing a Fallout game & paused it while we had dinner. After dinner he returned to find the computer was off and it would not turn on. It had been running fine until this happened. I checked the power supply with a multimeter, it seemed ok but to be safe I swapped it out with a spare 480 watt one, it still would not turn on. The MB is an MSI G31TM-P21, CPU Pentium D, 3.01Ghz, 4gig DDR ram, video card Geforce GT220, I tried unplugging the videocard, ram, HD & as mentioned swapped out the power supply & nothing. No lights no beeps, just dead. The funny thing is that if I unplug the 12v 4 pin connector on the MB that supplies the CPU, the fan comes on as well as the DVD drive works. Though I can't be sure I think the HD is spinning to. However no signal reachs the monitor which is expected since the CPU has no power getting to it. When I plug the 12v connector back on the MB its dead again. I suspect the MB is fried, but could it be the CPU? If it was the CPU wouldn't the system come on & at least try to post? I use a temp monitoring program & the CPU never runs hot. I am hoping its just the board, but wanted to ask some experts before I shell out the money for a new board. Thanks for any help, I have my kids for summer holidays & their PS3 is in the shop for repairs so this computer keeps them occupied & me sane. lol
OT though: I agree with the motherboard call. Try turning on the PC with only one stick of RAM and the CPU installed (no optical drive and no hard drive). See if you can get it running into the BIOS. If you can't, it's probably the motherboard. If it was the CPU or the RAM, the motherboard's onboard speaker would make this irritating beep-beep or one solid beeeeeeeeep noise constantly.
Thanks for the help, I tried removing the ram sticks one at a time & nothing, not a beep or a peep. I also read somewhere if the cpu was cooked you might smell something burned, but there was no smell. The caps looked ok no bulging or leaking. A mb is not so bad, $57 at a computer place nearby.