GA-Z87X-OC System won't shut down.

[thepan]

Hello guys,
I Am opening this post after experiencing a very strange issue. the computer always worked fine, but when I have changed the two fans of my H110 the damage happened!
The computer won't shut down anymore, windows closes everything but all inside the case still stays on. This is the second motherboard that does strage things, when I bought the first Z87X-OC I had to send it back because of this issue and they replace it on warranty. Now, after 8 months of usage with no problems at all it does it again. At first look I tought that it might be the case so today I got a new one but the problem is the same. It is very strange, when I press the on button, everything goes on but it doesn't boot....I have to press a second time to make the motherboard do his stuff and check the ports on the display.
To switch it off the only way is to press the I/O on the PSU. Hopefully you guys will give me a solution before send it to RMA!


Sys spec:
GA-Z87X-OC  Bios ver: F8 (latest before beta)
i7 4770k with H110
Corsair dominator GT 8gb 2133
Gigabyte gtx 980 g1 gaming
SSD Toshiba Q 256gb
HDD Caviar green 500
SuperFlowe Gold 850
Carbide Air 540
win 8.1 pro 64bit

Thank you in advance for all your help!

[thepan]

Up please

[shadowsports]

The only things that comes to mind are incorrect connections on the F_Panel header, something that is grounding to the board or having the CPU fan connecting to the wrong header.  As a matter of course, you should also confirm your PSU is not tired, faulty or having any other issues.   

[smeg90]

Thepan this happened to me. if your OC_ignition switch is turned on, on your motherboard then it will cause the problems you are having.

hope this helps