A co-worker’s computer worked before we moved offices and now it randomly shuts off. I’m at a complete loss on figuring out exactly what’s wrong.
I replaced the RAM, same issue. Reseated the cables, still not working. Computer isn’t overheating as everything is cool to the touch.
When computer shuts off, all the fans turn off but the power button light (that goes off when the computer is normally shut off) stays on. The network activity light also still blinks. Can instantly power the computer back on, but after a random period of time, it turns back off. I unplugged the DVD drive, and still had the same issue. The video card is on-board, same with the network card, and sound card.
I put the hard drive into a same model tower, and it seems to be working fine.
Am I right in thinking that at this point, it is most likely the motherboard that has failed or could it still be the power supply? I don’t see any physical signs on the motherboard, nor are there any special POST beeps during boot to give me any indication of where the problem would be. Any ideas or thoughts would be greatly appreciated.
Malcolm's Ramblings 
2 responses to “Co-worker Computer Frustration”
The blinking network light is the easiest to explain. Many puters have WOL=Wake On LAN, so they have to keep network components going to check for a wake up call. (The power light probably stays on to indicate that the computer is doing this.)
My best guess is overheating.
– Is the CPU fan still running?
– Did a wire move so it now gets in the way of the CPU fan?
– Did the CPU heatsink+fan unseat from the CPU?
– Try running one of those system-information utils that show what the various temperature sensors on the board report
CPU fan stops when the computer “shuts down”. I redid all the internal wiring when it first started. Heatsink + fan look secure. Temps are all within normal ranges. Power settings in Windows XP are all set to never turn off HD or Monitor. Screensaver is off.