pc power supply

[dannyday5821]

strange problem. my pc really struggles to switch on at all. i can, and when it loads, its flawless, games, music, internet - run perfect.

once i turn it off the problems start. if i put it to sleep - it wont turn back on. if i turn it off - it wont turn back on. no matter what. i try everything. nothing.

oddly - if i leave it for 12hrs it usually comes back on, like its no big deal. the worst was 24hrs.

im so confused what this is - once its on its perfect - and i can leave it on for hours on end playing it, pushing it to its max, never does it crash, fail or faulter - but as soon as its turned off... turning it back on again is an entirely different issue...

What The Funicular. anyone else have this problem?

[Wak]

Could the power supply unit have an intermittent fault and needs replacing?????
How old is the comp? Are the mains lead connections OK??