2013-06-10, 08:35 PM
Polantaris Wrote:I asked if the CPU fan was still turning on when he finally got it on today, and he said yes. This leads me to believe that it's not overheating, because it was off all day and wouldn't even turn on right away. Why would overheating prevent it from turning on at room temperature? It really seems to me at the moment like the PSU can barely provide the necessary power to turn on, and then afterwards cannot maintain that level and it turns off due to lack of proper power supply.
I don't have an adequate explanation; I can only say the exact same thing happened to me. My computer initially had similar inexplicable power loss after a period of time 10-15min. I attempted to diagnose the problem using various hardware monitor programs and came up with nothing unusual. The status then deteriorated until I could not power on the computer at all because it would fail to boot, getting as far as the Windows logo at best.
At this point, I attempted to replace the power supply which did nothing. I then broke out my DMM to try and determine if there was a short somewhere along the line (there wasn't). After much frustration and head scratching I noticed some slight discoloration near the CPU fan and decided to use a heat probe when I turned it on.
Despite several software programs reporting normal temperatures, the CPU sensor area was reaching over 100 C and simply reporting it incorrectly. It's rather remarkable the safety shut down functioned properly.
If I had to guess the exact cause, repeated shut downs due to overheating triggered some secondary precaution related to fan monitoring. It seems a bit far fetched, but simply swapping fans did the trick and I've been fine ever since. If I were less frustrated and more inquisitive at the time, I might have tried simply unplugging and reattaching the fan to see if that allowed the OS to boot.
It could easily be the power supply; I just wouldn't rule out overheating until actually tested.