PSU with 20 & 24 pin pwr

Firblog

Hi

Looking for a replacement psu for Dell XPS 700, model DCDO, PSU Model H750P-00 can see spec here.
Or if someone can recommend one that will do the same job please reply.

Cheers

yoyo

If it's an ATX PSU (that description confirms it is) any ATX one should work, just make sure to get a reasonable one (Corsair, Antec etc.) and one that will cater for all your hardware (check SATA power cables (can get molex->SATA if neccesary), PCIe power, cpu power etc). Most PSUs will come in 20/24 Pin configuration. The additional 4 pins are only used if you are using a PCIe video card afaik,

Nick

Firblog

Not a normal PSU or motherboard, Seems this PSU has

CONNECTOR:
P1 24 PIN CONNECTOR
P2 20 PIN CONNECTOR

as in 1 X 20+4 pin & 1 X 20 pin power connectors, have tried normal 20+4 pin psu... lights come on but no boot, there are 2 power connectors on the board, one for the 24 pin and one for the 20 pin..

Gonna try hooking up 2 normal PSUs, see if that gets it going...

Have uploaded pic of the motherboard, connectors @ bottom left & top right..

roast

yoyo wrote: »

The additional 4 pins are only used if you are using a PCIe video card afaik,

Nope. There can be a further 4 pin port which is just for CPU power, this is a separate port in addition to the 24/20 pin port.
A 6-pin is used for PCI-Express cards.

OP, what is the motherboard model number/part number?

yoyo

roast wrote: »

Nope. There can be a further 4 pin port which is just for CPU power, this is a separate port in addition to the 24/20 pin port.
A 6-pin is used for PCI-Express cards.

OP, what is the motherboard model number/part number?

Yeah wasnt clear there, older mobos with only 20 pin ATX don't support PCIe, afaik all PCIe video cards need the additional 4 pin power (most PSUs come with a 20/24 pin ATX power along with an additional 4/8pin connector for Intel CPU-Don't think AMD ones need it although not familiar with the newer ones).
Sorry OP but whatever standard Dell are using there I don't know, looks like you'll need to find a particular "Dell" PSU, I got the impression as the site said it is an ATX one it was fairly generic

Nick

roast

yoyo wrote: »

Yeah wasnt clear there, older mobos with only 20 pin ATX don't support PCIe, afaik all PCIe video cards need the additional 4 pin power (most PSUs come with a 20/24 pin ATX power along with an additional 4/8pin connector for Intel CPU-Don't think AMD ones need it although not familiar with the newer ones).
Sorry OP but whatever standard Dell are using there I don't know, looks like you'll need to find a particular "Dell" PSU, I got the impression as the site said it is an ATX one it was fairly generic

Nick

Most, but not all. It's 6-pin btw, sometimes even two of these connectors. The ones that don't are generally "green" low-powered graphics cards.... and generally suck! :pac:

OP, what wattage is the PSU also? That's a fairly hefty PSU to have two ATX (20/24 pin) connectors... and I'm finding it hard to understand why both are there, there really wouldn't be any benefit, even in waaaaaaaaay higher-end machines.

Perhaps the Mobo is used in multiple different Dell models....where the case differs (like the PSU being at the top of the case in some, and the bottom of the case in others)
My point is, I don't think both are required for normal operation.

EDIT - just saw your link re: the current PSU. There's slightly different pinouts on the 20pin and the 20+4 pin, due to the latter being ATX 2.0

yoyo

roast wrote: »

Most, but not all. It's 6-pin btw, sometimes even two of these connectors. The ones that don't are generally "green" low-powered graphics cards.... and generally suck! :pac:

OP, what wattage is the PSU also? That's a fairly hefty PSU to have two ATX (20/24 pin) connectors... and I'm finding it hard to understand why both are there, there really wouldn't be any benefit, even in waaaaaaaaay higher-end machines.

Perhaps the Mobo is used in multiple different Dell models....where the case differs (like the PSU being at the top of the case in some, and the bottom of the case in others)
My point is, I don't think both are required for normal operation.

EDIT - just saw your link re: the current PSU. There's slightly different pinouts on the 20pin and the 20+4 pin, due to the latter being ATX 2.0

I'm not talking about the PCIe 6pin power, new PSUs typically come in 20 pin with 4 detached (similar shape to the CPU 4 PIN), its used to supply more power to the PCIe video cards, see here. Having a 24pin and a 20pin connector on the one board does seem hugely excessive, as multi video card configurations do not need such a configuration (provided a decent PSU with decent wattage is used). My suspicions are that its done intentionally so replacing the PSU is made more awkward

Nick

roast

yoyo wrote: »

I'm not talking about the PCIe 6pin power, new PSUs typically come in 20 pin with 4 detached (similar shape to the CPU 4 PIN), its used to supply more power to the PCIe video cards, see here. Having a 24pin and a 20pin connector on the one board does seem hugely excessive, as multi video card configurations do not need such a configuration (provided a decent PSU with decent wattage is used). My suspicions are that its done intentionally so replacing the PSU is made more awkward

Nick

The additional 4-pin (separate from the 20/20+4) is for additional CPU power, not PCIe.

Firblog

Have sourced the Dell Manual for the machine here so you can see the wonderful weirdness of it all... number 8 & 22 are the pwr connectors I've pointed out previously

Haven't come across one of these before, so am a bit tentative about ordering a power supply for it without seeking a bit of advice before hand.

It has a Nvidia GTX 8800 graphic card that requires both DC pwr connectors (3 & 4 on the diagram) to run

Have sourced this replacement supply today, and just really wondering if anyone can say that it's the right or wrong one from looking at the diagram.

Cheers for any advice.

yoyo

roast wrote: »

The additional 4-pin (separate from the 20/20+4) is for additional CPU power, not PCIe.

This is what I'm talking about, the CPU power one is seperate like this. I'm fairly sure the ATX additional 4 pins are for the video card rail, the site above suggests so also anyways back on topic.
Firblog, i'd say that PSU is ok, it states it has both a 24pin and 20pin connectors

Nick