The problem is that the computer will start for a random amount of time, it may be anywhere from a quarter of a second to a minute or so. When it does start up for a minute or so, I can get to the POST screen, and windows will start up, but eventually the system will shut off. The computer is an Asus Essentio CM5570-AP003, which I bought last christmas, whose specs are as follows:
CPU: Intel Pentium Dual Core @ 2.60 GHz
Motherboard: Not sure, really... doesn't say on the motherboard, and I can't find my comptuer on the asus website.
Memory: 6GB DDR2 (3x2GB)
CPU cooler: stock
Primary Video: ATI Radeon HD 4770
Hard Drive: Seagate Barracuda 7200.12 750GB
Power Supply: Thermaltake Purepower W0100RU 500W
and some random DVD drive.
I have upgraded my powersupply, to accomodate the gpu, which i did at the same time I bought the computer. I haven't changed a single piece of hardware since then.
I took out the gpu, and put the stock PSU back into the computer, but I get the same results. I have also unplugged power from everything but the motherboard, and I get the same results.
Unfortunately I don't think this motherboard has a speaker built into it, and I don't see any slot for a speaker to go into, so trying to listen to system beeps is impossible. The only problem I have found is that the CMOS battery was leaking a little bit, but I will be going soon to buy a new battery, however I don't think that is the problem. Hopefully someone has a suggestion as to what I could try? It has been working perfectly fine for the past 8 months.
I certainly wish I had a spare motherboard just laying around. I'll check the CPU heatsink and fan, but if that doesn't work, I'll just have to take it up to a local computer shop where im sure they have spare parts to test on.