Motherboard and PS compatibility

[GrowingSlowly]

Well, I have a question. I was interested in replacing the power suppy in my primary system so that I could use it's quiet (but small PS) in another system that will be located in the bedroom. Seeing as I am always looking forward towards the next up grade, I purchased an Antec Truepower 550 that is SLI compliant. I figured that whenever I do upgrade, why not have the power available and in the right package to do the job. I am trying to connect it to my Abit NF7-S.V2 motherboard and something just doesn't seem right. The PS comes with a 20 + 4 pin connector. The 20 pin connector will disconnect from the 4 pin connector and it fits right in to the main socket on the MB. The problem is with the remaining 4 pin connector.

The NF7-S.V2 board has a seperate 4 pin 12 volt connector right next to the main 20 pin connector. If I am reading the MB manual correctly, this is for the other 12 Volt ATX connector. It seems that I should be able to connect the +4 pins of the power supply there. I tried this and when I turned on the PC, nothing. Now if I disconnect the +4 pins, then I can boot up and run successfully. My old power supply also had the 4 pin connector and I never had a problem running while it was connected.

So what are your opinions. Am I doing something wrong? Is the Power Supply bad? Is it a compatibility problem? Should I just run withou the +4 pin being connected? Maybe the problem will fix itself when I finally do upgrade to an SLI system and get a new motherboard. But that may not be for a while, and I do need the old power supply somewhere else.

System
Abit NF7-S.V2
AMD mobile 2600 (clocked @ 2300 mHz)
1 gig OCZ memory
Win XP Pro

Thanks for the ideas

[alwozniak]

There is only one class fit for a 24 pin to 20 pin connection. Four pins will not be connected are are not needed. Find the proper fit and go.

[pandaz3]

Okay I think you are asking about which of the two four pin connectors goes into the four pin port. NOT the one that can piggy back on the twenty pin connector. You need the other squareish four pin connector called 'ATX 12V' or sometimes 'P4' connector. It will have a lock on one of the four sides in the middle of two pins. You will see a corresponding lip on the port. It is necessary to use this connector. The other four pin that had been piggy backed is not needed. Tiewrap it away.

[GrowingSlowly]

Yep andaz3, you are correct. I had 'lost' the ATX12V connector in the mass of PCIE and SATA connectors. I went back and unbundled all the unused connectors and there it was. It now resides in it's proper place. Thanks a bunch. You nailed it.