Proprietary Connection Problems

[Jaune_Pendragon]

HI. I have a HP 280 Pro G3 MT. Its power supply died and I am NOT looking forward to purchasing a replacement power supply from HP.

 

Now here's my question. My board has three 4 pin connectors and one 7 pin connector. 

 

Can I use a normal PSU to power it? with an adapter for the 7 pin connector? 

 

Also does all 4 pin connectors supply 12V?

[Kid.Lazer]

YOLO-ing it with an off-the-shelf PSU is probably going to fry your board as well. Have you checked places like Ebay for a cheap, used replacement PSU?

[PDifolco]

Nah you can't use a normal PSU, gotta change the board as well (and then maybe the case too)

Joy of OEM prebuilts !!

[Jaune_Pendragon]

22 minutes ago, Kid.Lazer said:

YOLO-ing it with an off-the-shelf PSU is probably going to fry your board as well

will it fry the processor if I try anyway?

[Kid.Lazer]

If the voltage or polarity in every pin isn't exactly what it's supposed to be, it will for sure ruin something.

[mariushm]

The 2  4 pin connectors are most likely standard CPU 4 pin connectors.  But you can double check that with a multimeter on DC voltage measurement mode.

The power supply does output 12.1v instead of 12v  but it would be perfectly acceptable to have 12v and it would still work.

 

The 7 pin connector should have the wires that tell the motherboard the power supply is ready to start (PWR_OK from the 24 pin connector),  the PWR_ON through which the motherboard can tell the power supply to start, and probably there's also a 12v stand-by wire (instead of 5v stand-by)

 

You could try to open the power supply to see if it says on the circuit board where those wires from the 7 pin connector go, what those wires do... can't go by the colors.

The stand-by you could probably figure out with a multimeter.

You could probably figure out which one is the power on pin by trying to short that one to a ground wire (probably the black wire, or the black wires from the 4 pin cpu connectors, but you need to double check it.

With nothing connected to it, the power supply plugged in should output the stand-by voltage on a wire, and some voltage (usually 3-5v) on the PWR_OK pin, so you can figure that out

The 7 pin connector may also have the pwm signal wire for the power supply fan (so that the motherboard could adjust the power supply fan's speed, because being a small form factor pc, probably the power supply fan also behaves as a cpu cooler fan.  With atx power supply the mobo won't control the psu fan, so you'd have to be careful about cpu cooling.

 

So you could make your own adapter cable once you know what each wire in that 7 pin connector does, but most likely you're gonna need a 5v to 12v step-up regulator / dc-dc converter to boost 5v stand-by from the ATX power supply to the 12v the motherboard expects, IF the motherboard expects that (I could be wrong).