AB350 Pro4 CPU Power Issue

seahawksfan wrote: Is it possible 500 watts is just not enough?  Could that be why it's doing this?

Without us knowing you system parts list, that'll be impossible to answer.

seahawksfan wrote: Hi all, I'm having an odd issue.  When I plug the CPU 8 pin power into the motherboard, ev. spins up fine and then the motherboard/computer shuts down and powers back up on it's own.  When I boot up without the CPU power in it appears fine - although doesn't post. I have everything imaginable including messing with the memory, removing the heatsink, removing the CPU and replacing it.   The power supply is a Cooler Master 500w, Ryzen 3 and Corsair Dual 4GB Mem. Any ideas? Thanks.

The test without the CPU power cable connected is not valid, since the CPU does not run at all.

Have you cleared the UEFI/BIOS with the jumper on the board?

So does the PC start at all, after the board starts, stops, and then starts again? Or does it continually repeat the start - stop cycle?

Do you have an OS installed? Does the PC run normally after a start - stop - start cycle?

What is the full model name/number of your PSU? What video card are you using?

Sorry but not much detail in your description, difficult to know exactly what is happening.