PC powering on intermittently very weirdly...

[WeeHobbitMan]

Here is one for you guys, fairly new PC build non problems for about 2 months then all of a sudden PC would not power on via power button... Went through the usual checks, is it plugged in, are all connectors fit not loose etc all fine... Sometime after 2/3 attempts at mashing the on button it would power up other time it would take a good 10 mintues of me pulling the case apart checking everything whilst mashing the power on button.

Even tried swapping reset and power buttons around to rule out the button itself. No biscuit.

So anyway after scratching my head cleared CMOS and it powered up... Great!

Try to chang any setting in BIOS to do with CPU such as setting to XMP or attempting my overclock again. PC shuts down, won't power up again...

Clear CMOS again, mash power button repeatedly till it powers up, rinse and repeat...

Not come across this before any one have any ideas???

Build is
I5 4590k
8BG Corsair Vengeance Ram
Sapphire R9 280x Vapor X
Asus z97-K Mother board
H80i cooler
Corsair 750w RM PSU

 

[boosted1g]

If it works with cleared bios just fine, but not with custom settings then the issue is with your overlclock or other settings.

 

[ronintexas]

Have you tried with standard settings non-stop for a while? (No overclocking) Does it power up consistently (even while it is off for a while)?

 

[WeeHobbitMan]

Have you tried with standard settings non-stop for a while? (No overclocking) Does it power up consistently (even while it is off for a while)?

Yeah, same issue, will just about give up sit down and hit the power button out of frustration and it will power up!
It's not even powering up straight away after clear cmos now, took me 10 minutes to get it to power up this morning

On a side not used the ASUS ez tuner out to see if that had any effect and it just shuts down straight away and won't power up till I clear CMOS,
Once its power on, works fine, I can stress test it, play all my games no problem.

Interestingly if I put it into sleep mode I have the same problem waking it up via power button but no way near as bad

I've stripped it down and rebuilt it and same problem! Pretty sure its not the power button itself, reset works perfectly,

 

[ronintexas]

Have you tried updating the BIOS - it sounds like there is an issues with the BIOS on the mobo - updating it may fix the problem - if not, I would bet you have a bad mobo.