So I have strange problem. When I start the computer, the fans are starting (VGA and CPU), HADD also starts spinning but no beeps or picture. After I shut down from the PSU and try it few more times the computer starts normaly and I have no problems what so ever. Here is the build.
MB: Asus P5KC (last bios update)
CPU: Intel Pentium 4 511
RAM: Upgraded from 1GB DDR3 to 2x2GB DDR3 A-data (had to flash bios for compability)
VGA: Nvidia GF8600
PSU: 400W not branded
So I suspect the PSU is the problem but im not 100% sure. If someone had the same problem please share your knowledge.
It sounds like a PSU problem, assuming you have tried another outlet to plug the PC in.
It could also be a motherboard problem, even a CPU problem (these 2 problems are difficult to distinguish because they have similar symptoms). The best way to confirm is to swap in a known-good power supply and see if theres any difference.
Thats what Staples would charge you $100 something to do for their "diagnostics fee". You'd be better off buying a cheaper new PSU, at least if that isn't the problem you could use it for a new system build, that thing is pretty weak by modern standards. $30 bucks with promo code and mail in rebate, pretty good PSU for the money: