24 Pin Problems

1298ty

Distinguished
Sep 5, 2011
13
0
18,510
I haven't been able to boot or post my 9-month old PC for quite some time. After RMAing the motherboard, I get it back today and it still wont POST. I've followed every step in the guide and I get nothing.

So I've been trying to identify the faulty part and this is the process I've been going through:
1) Connect case fans to PSU (case fans come on)
2) Connect 8-pin CPU connector (cpu fan comes on)
3) Connect 24-pin connector (everything shuts off)
4) Unplug and Replug PSU power cord until it starts again
5) Repeat

Specs:
Asrock AMD 990FX Professional Motherboard
PC Power & Cooling MkII Silencer 500w PSU
HIS AMD Radeon 6850

I'm leaning towards the power supply, but I want to be sure before I start replacing things. Any help is seriously appreciated.