Remove all hardware connected to the motherboard except for the processor, one memory module, power supply.
Remove all add in cards (note the positions), disconnect (power and data cables) all hard drives, optical drives floppy etc.
If there is on board video, remove the video card and connect the monitor to the on board video port, otherwise leave the video card in place
See if you get a bios post. If not try another memory module.
If you get a bios post start adding hardware back in one at a time and test for bios post each time until you find the bad hardware that prevents a post screen.
If no post, you will need spare parts (Video card, PSU, CPU, Mobo) to troubleshoot it.
2Not an expert on this, but I had similar problems with a self-built system I had once, and it was the motherboard. – GreenMatt – 2011-04-23T20:52:15.123
^Thanks. Answers like these is what I need. I dont want to but a whole new replacement motherboard, to find out that its not the problem. – ctzdev – 2011-04-23T20:55:06.837
possible duplicate of Computer Turns on Briefly then right back off again.
– Wuffers – 2011-05-07T17:09:37.850I've had happen over the years many times, and it's always been the RAM, power supply, or motherboard. If you eliminated the other two, I would put about 95% certainty on the motherboard. – BlueRaja - Danny Pflughoeft – 2011-05-07T18:23:56.710