GA-P55A-UD3 shuts system down

[Dark Mantis]

Check in the BIOS and see if the Legacy USB Devices (or similar) is enabled.

[deveng]

I did check that and its enabled. 

I also tried a Fedora Live CD.  It tries to boot up and then shuts the system down.  I tired a CentOS install on and it starts up and during the install it shuts the system down!

What else?

[Dark Mantis]

Try disabling Legacy USB Devices   also the USB3 and SATA3 controllers if you are not using them.

[deveng]

Tried disabling the Legacy USB but since I'm using basic USB mouse and keyboard, they don't work when doing that.  I also disabled the USB3 so its supposed to run USB2 only.  That didn't work either.  Using a stick in the USB port still shuts downs the system.

I also tried using just single memory sticks (tried both sticks) USB still crashes system.

BTW,  my RAM is 1.67v Muskin DDR3 dual channel.  Since the motherboard automatically sets the RAM voltage at 1.58v,  I bumped it up to 1.64v.  System booted fine and RAM tests were good, but USB problem did not go away.

Anything else?

Regards,
Jeff

[Dark Mantis]

Well that could just have a bearing on the problem as these motherboards are designed to run the memory at 1.5v. So if the RAM will run at that it would be worth trying.