Old Antec PSU was getting noisy and I wanted to replace it. Got a new OCZ 600 watt. Shutdown system, removed old PSU, routed cables and re-attached the new one. Powered up and got nothing. The PSU passed the paper clip test. Removed all cables but the 24 and 8. Removed battery, reset CMOS and still nothing. I actually re-attached the old PSU and that didn't work but that didn't pass the paper clip test either. Ideas ?