Fatal1ty Z97 Killer works once for 10 minutes

I have created a sticky about clearing CMOS effectively, you can try the method I outlaid and see if it helps. Your symptoms are indicative of 2 potential problems I can think of.

1. Bad overclock settings, which a clear CMOS should fix

2. Bad power getting to the system, try reseating all the power cables and look for any potential shorts, screws under the motherboard, nicked wires etc.

Good luck

Your parts list is solid so unless you got a defective PSU I don't think a substandard PSU is the problem. Looking at your parts list and based on the fact you are posting here I assume you have another system operational?

If so you can try using it's PSU on a bare bones boot of the new system. Just motherboard and RAM and see if the system posts.

If it does not then that should rule out power as the problem completely. Then the next step is to carefully check for bent pins with a magnifying glass. Also be sure you have not over tightened the CPU cooler, too much pressure on the CPU can cause the pins to shift out of alignment. Another thing you can try is to power on the system with nothing installed, just the power connected. The fans should spin up in this case, if not then it is likely that the board is the fault. From all accounts I have heard here on the forums the ASRock RMA procedure is fairly reliable. Don't lose heart, this kind of thing happens all the time with boards from all manufacturers.

Try the things I mentioned above and post back if they don't work and we can see what other steps can be taken.

Good luck with your RMA