Old s939 mobo needs extra 4 pin 12v power connecter, new PSU doesn't have it

[Sureshot324]

My main system is running an Opteron 170 on a s939 pci express DFI NF4 Ultra-D board. It stopped being able to boot, and I think my PSU was the problem because I stuck in an old PSU 350W and it booted fine. However, the old PSU is from before PCI-E, so it only has a 20 pin main connector, not 24 pin, and it doesn't have the PCI-E 6 pin video card connectors. The only way I could get it to boot with this PSU is to use my old 3dfx Voodoo 1 PCI video card.

So, I got a brand new OCZ 800w PSU, since I'm gonna need it anyway in 2 months when I build my Nehalem SLI system. The problem with this PSU is it doesn't have the extra 4 pin power connector that my mobo needs. My mobo has the regular 24pin socket (also works with 20 pin), and a 4 pin 12v power socket, and lastly an optional 4 pin hard drive type connector (apparently for extra overclocking stability).

The 4 pin 12V socket next to the CPU is NOT optional (I tested this with my old 350W PSU), even if you connect the 4 pin hard drive type connector. Is there any adapter cable I can get that plugs into this socket so I can use my new PSU?

 

[Sureshot324]

I think I answered my own question. Instead of the 4 pin connector my PSU has an 8 pin connector, and you're supposed to only plug in the right side of it. Unfortunatly this won't work on my mobo since there's no room. There's a capacitor on one side and the 24 pin connector on the other. Guess I'll have to find a 4 pin extension.

 

[Yellowbeard]

Does that 8 pin connector slit into 2 halves?

 

[MarcVenice]

Yeah, you might be able to 'break' the 8 pin into 2x 4 pins? Are you sure the 4 pin connector is needed though? My s939 mobo is 20+4 as well, but with my old psu, which only had a 20pin mobo connector it still ran fine, in fact, with my new PSU, adding the 4 pin made no difference whatsoever.

 

[Arcanedeath]

That DFI board just won't boot w/out the P4 conector its required you get beep codes or no post when its not connected.

 

[Yellowbeard]

Originally posted by: Arcanedeath
That DFI board just won't boot w/out the P4 conector its required you get beep codes or no post when its not connected.

Very true, those boards were very demanding AND picky about PSUs.

 

[RallyMaster]

Originally posted by: Yellowbeard
Does that 8 pin connector slit into 2 halves?

I know my Corsair PSUs do

 

[VirtualLarry]

Just remember that the 8-pin that splits into a 4-pin and 4-pin other half, for the ATX12V connector, is NOT THE SAME as the 4-pin that is part of the 20+4 pin. Totally different, and you will fry something if you screw those two up.

 

[Sureshot324]

I called OCZ and they said they'd ship me a 8pin to 4pin adapter. It's going to take a while though because I'm in Canada and they're shipping from the US. I'm tempted to try to break the 8 pin in two, but I think I'm just going to hang on until the adapter gets here.

 

[Sureshot324]

I got the adapter yesterday but it still won't boot with the new power supply. The fans all spin but there is no signal on the screen. So the situation right now is it will boot fine with the old 350W powersupply, with the 480 watt it will take several tries but eventually will boot, and with the new 800 watt it won't boot at all. Also, it won't boot with a PCI-E video no matter what powersupply I used (I've tried 3 different PCI-E video cards). The only way it will boot is with my old PCI 3dfx card.

So is it safe to say my mobo is fried? Guess I need to start looking for an old socket 939 board.