ATX12V 4-Pin, odd problem

[campingcarl]

I just recieved my new power supply for my computer I will be OCing soon. I hooked it all up, hit the button, and nothing happened. For some reason it wont even POST if the 4pin 12V connector is plugged in. I had a Antec True430 and It used to fine, it broke so I used a generic PSU for a while and it worked fine without it as well. Now my new one is an Antec True430 but its one of the newer ones with SATA connectors, ect. I dont get it at all. It would make sense if it wasnt plugged in and didnt work but now I am just confused.
Specs:
P4B533
P4 2.0Ghz
Antec True430

Now I would think I would want this if I was OCing, or is it not needed with this PSU? Thanks in advance

 

[Flyingfenix]

First of all (dumb question): Is the ATX12V connector plugged correctly on the motherboard? Usually it would not fit any way that is not right, but if you apply enough strength...

Second: Look at:

http://www.formfactors.org/developer\specs\ATX12V PSDG2.0 Ratified.pdf

...at page 33/35 and see if the wires are inserted correctly into the connector.

Third: Turn your PSU on (short the green wire to any of the black ones on the main DC connector) and, with a voltmeter, measure voltage between the yellow and black wires on the ATX12V connector. It must read 12V +- 10%.

If not you should RMA your PSU as it is defective.