Computer restarts after shutdown

[DragonTamer1]

After killing my last motherboard through stupidity, I bought this replacement Gigabyte x79-UP4 motherboard. After messing with it and finally dialing in the settings to get it working I'm left with the one major issue of the system won't shut down. Doing a soft shut down works for about 5 seconds before it comes back on.

 

Things I've done to try and fix this issue.

-disabled wake on LAN (all possible combinations in OS and BIOS, currently both are off)

-verified wake on timer is off

-disabled resume from S5 state in BIOS

 

This issue doesn't seem to be specific to this motherboard but given the fact that some parts of the BIOS just don't work it wouldn't surprise me if something else is going on there.

 

I've also heard that it could be a pinched wire waking it but I don't see how that would work. If the power button wire was pinched then the system would not power on with a button press and would shut itself down while powered on (like holding the power button).

 

I've also read that it could be the power supply not supporting the sleep state, but it did on my last board unless there is something different.

 

The power supply is a SeaSonic X850 and the old motherboard was a MSI x79-GD45+.

 

Looking for any ideas to try, the system can be shut down but I have to do a soft shutdown, wait for the restart and hold the power button while it's posting.

[Halic99]

I've had the same issue i'll turn my computer off all the way but it'll restart instead of turn off completely

[Praxis727]

power it down and unplug your power supply.  Hold the power button for 30 seconds.  That should discharge it.  You should also consider your mobo may be touching the case somewhere.  As a precaution I recommend taking it apart one by one and reassembling it and testing with each new piece.  So on stick of ram and onboard.  Then add the next stick.  Vid card and so on and on forth.  Dont check to see if cables are tight.  take them out and reseat them.  Very common mistake.