Trouble starting the computer. Need Help

[Gux]

I have had some trouble for a year now, to start my computer. It's such a weird problem that it doesn't make any sense to me.

Sometimes when I try and turn the PC on nothing happens, like there is no power going to the PC. But if you cut the power completely from the mains and then back again, after 20 seconds the PC starts with no problems.

This has happened on my old Athlon 64 build and the new Phenom 1090t build. At first I though it might be my old case and it's old power button but after changing the case, same problem. I have kept my old PSU from the Athlon 64 computer which I bough in 2007 and is a Coolermaster Igreen 500w series.

Now I would suspect that the PSU is acting up, but there are never any problems while the computer is on, even when you play games or do benchmarking on 100% load.

If the PSU was broken surely it would show up when stressing it to the limit and not when trying to start the computer up.

Any help on this issue?

Thanks

 

[Gux]

probably a dodgy capacitor, taking time to charge up.

Time for a newer PSU?

Dunno but when you turn the power off from the mains and back on, the computer start instantly without problems. If it did take up time to charge up, why does it charge up instantly when you switch the power off/on from the mains?

This is a really weird problem that makes no sense to me. Also this only happens occasionally, you can start up the computer 10 times and this might only happen once or twice. As I said before other than this problem, everything else works fine, no BSOD, no slowdowns, no crashes, everything rock solid even when stressing the computer to the max.

Also if you put the computer to sleep and not fully turn it off, then there is no problem what so ever. This only happens when you turn off the computer.