No RAM POST every boot

[atynd]

CPU: Dual Xeon x5670

Motherboard: Supermicro X8DTL-iF

RAM: 6x4GB Hynix HMT151R7TFR4C-H9

PSU: 500w EVGA Bronze

I've been trying to troubleshoot this problem for a while now and have run out of things that I can think of. When I shut the machine down and try to boot it up again, most of the time it fails to boot and gives a no memory POST code. I can fix it by flipping the switch on the PSU off for a few seconds, and then flipping it back on and booting again. I've tried replacing the 3V battery on the motherboard, run a ramtest for approx 3 hours and found no errors, and tried removing some RAM sticks and running the RAM with different configs and the error still occurs. I'm wondering if there are any more troubleshooting things I can try.

[SpookyCitrus]

Sounds like it could be a problem with the motherboard itself.