Power supply Help needed

Brassman · 23 Jan 2007 at 10:31

Hi guys first time on here, i have fitted a "Sapphire x1950pro agp"graphics card which needs a power supply with 30amps sustained on the 12v rail,so i bought a corsair 620w hxuk(3x 12v rail with 18a per rail) it will not start the pc in any shape or form , my mobo is a winfast nf3250k8a i thought it was the psu at first so got a replacement and still the same afer doing the paper clip test the psu seems ok . corsair say the mobo is not compliant!! the mobo is a 754 socket for an athlon 64 3000+ cpu ,what i want to know is if i leave my old 550w psu in the pc
plugged into the mobo,and take wires off the green and black to the green and black on the 20 pin plug on the new psu, the pc will start up and also power up the new psu can i then use the new psu to power the graphics card,etc thus run two psu,s i am finding it difficult to find a mobo that is compatable

james.miller · 23 Jan 2007 at 10:35

what does 'not compatible mean'? how isnt it? have you plugeed the 4 pin atx12 lead in?

Brassman · 23 Jan 2007 at 11:33

i plugged the 20pin connector in,i plugged the 4 pin connector onto the mobo beside the cpu,and connect eveything else and nothing happens the fan in the psu does not even spin,sorry corsair said the motherboard is non compliant!!as soon as i put my old psu back in it works no problem(apart from not enough amps for graphics card) the mobo was bought lasr year and the old psu bought fo£20 June last year. i to found corsair reply puzzling.

Yewen · 23 Jan 2007 at 14:14

It is an ATX board (right?) and a ATX 2+ PSU so they should be 100% compatible, if they are not someone is not conforming to the ATX spec (should be an impossibility) or you are doing something wrong.

split · 23 Jan 2007 at 14:57

In the past on here, some PSU's just dont get on with some motherboards.
There was threads on here, and on places like DFI street / MSI forums etc about no boot issues with some combinations.

I have seen it suggested in the case (corsair forum)

I'm pretty sure that the motherboard is not fully compliant with the ATX 2.2 to 2.4 specs, as we've seen this issue with another motherboard. That other motherboard was by Winfast/Leadtek, but the issue was nearly identical. Chances are it's looking for an out of spec reading on the +5sb rail, which is a very common problem with older motherboards made before the ATX 2.2 spec was finalized.

IIRC, it was the +5 volt rail that was the issue with DFI / MSI and some PSUs even though they are all made to the same standard.

You would think they would have ironed out these problems, and maybe it is the 'ironing out' by changing some rails that is not getting on with an older board.

Brassman · 23 Jan 2007 at 17:40

i think that the last quote is a reply they gave me from the corsair site
the only difference i can see in the power supply's is that my old psu has an extra wire in two of the end pins, anyone got any suggestions ?may be running the two together as in my first post or is it to risky? i have about £290 tied up that i cannot use :mad:

surely you would have thought the corsair would do the job i thought it was tip top gear !!

split · 23 Jan 2007 at 18:03

surely you would have thought the corsair would do the job i thought it was tip top gear !!

So is OCZ, but some people couldn't get then to work on the MSI Neo 2 board.
Same with Seasonic and DFI board.
It didn't affect all users tho, but it's a pain when it does.

I can't get to the threads on DFI street but for example MSI board thread..

TIP: if you experience problems with Antec Neopower and Truepower PSUs and also with PowerStream PSUs, try Bios 1.37 and turn the PSU off after you shut down, seems to help as well

The problem was just no boot as you get due to some 5volt rail setting on newer motherboards that didnt get on with MSI boards.
There was a huge row with DFI and seasonic with one blaming the other, but it didn't affect all users.

It just shows that the best gear in the world (your motherboards a bit of an unknown) just don't always work together.

I think it some + or - thing on the 5 volt rail that makes the psu not fire up.

Brassman · 25 Jan 2007 at 13:40

so does any body know if you can use two psu in one case so i can get this graphics card to work without spending any more money? have read some threads about it and it looks like it can be done anyone done it? :confused:

split · 25 Jan 2007 at 14:21

The old Coolermaster stacker used to have room for 2 PSU's, and came with a connector so it could be done. ( cable ) I'm also thinking thats for 2 x 20 pin as well.
There are a few guides around the web such as here on how to get 2 PSU's to work.

I cant see that guide helping you tho as you need to hot wire your new PSU to get it to turn on, and that means the 24 pin atx can't be plugged into your mortherboard.
I would suggest going back to the corair forums and see where you stand at getting a refund.

You also might like ti look here at ATX standards (the PDF files), but I doubt unless you have the full schematic of your board and the PSU it will help.