System not booting up

Ok, an old system of mine has had a steadily more common problem, which is now really getting on my nerves. If I turn the system off by any means, it won't boot back up again unless left turned off for about 20 hours. I used to be able to pull the plug, press the power button, insert the plug, then it would work again (When the problem was smaller), but now it rarely will turn on.

It DOES turn on, but nothing appears on the monitor, and there are no BIOS beeps at all (No errors, no single beeps to show everythings ok). *sighs* Anyone have a solution?

750mHz Athlon
312mb RAM
GeForce3 Ti200 (Doubt this has anything to do with it)
And an old VIA motherboard, not sure of the make/model though.

 

Check the motherboard for blown capacitors, look at the capacitors and see if any are bulging or if there is any brown residue at the base of them.

 

check out the power supply