PC automatically shuts down.
I have a K8VGA-M motherboard, AMD Sempron 3400+ CPU, 600watt psu, 1.5GB memory, 120GB HD, nvidia 6200 GC and the usual mouse, keyboard, etc.
My problems started this morning. Used PC last nite and it was fine. This morning it shut down on me after about 2-3 minutes then restarted again a few seconds later then shut down again. The shutdown is sudden like a loss of power. Occasionally their was a few beeps like a 'nee naw nee naw nee naw' until I switched the damn power unit off. I opened the case and checked everything. Removed the CPU and checked the paste which I applied about a month ago and put the CPU back, fan plugged in, etc. All looked good but again it shut down and this time it didn`t even POST and the keyboard (USB based) would not work. Changed the keyboard for a plug in one (not USB) and this one worked yet the PC would not reach POST. Removed the 512MB chip and tried again. Got to POST then it switched off again. Replaced the chip and removed the 1GB. Same again.
The PC takes a good 5-10 seconds to come on once the PC is switched on, the network lights for the Ethernet cable come on, go off then come back on again before the PC powers up and shuts off. I am at a total loss as it worked ok yesterday.
The PSU was from Ebay as was the mobo.
Quick Addendum: I did replaced the 13 Amp fuse in the PSU plug before it started going batsh*t crazy and not getting to or beyond POST.