My brother put together a computer for my dad ages ago except he bought a power supply that wasn't compatible with the motherboard. Board had a 4 pin CPU cable and PSU had an 8 pin CPU connection. Except instead of returning it and getting a compatible one he just jammed the cable into it.

Anyway, my dad was trying to get it working again and seems to have knocked the PSU. He ordered an exact replacement from Amazon but I told him to return it and get a compatible one.

But he has no idea what he's doing. (I have no idea what the components inside the case are).

Is there an online (or not) shop that he can contact and they can help him over the phone to identify what power supply is needed? Or is there a good shop to take it into to get one? I can go to fit the new PSU but can't be there at the time of him ordering it.

You may find this of interest.

The Corsair website certainly seems to indicate that their PSU's have an 8-pin connector that splits in half specifically for this purpose.

Thanks, so looking at the connections it seems that some of them are shaped to show the correct way up. If you were to plug this in the wrong way up would it ruin the power supply or is there a chance that the board is also screwed?

My understanding is that the pins are different shapes to prevent insertion the wrong way round (without applying excessive force). I really have no idea what would happen if you managed to hammer it in upside down.

Yeah, my dad used excessive force after removing the clip that's supposed to hold it in place because it was "getting in the way".

With an 8 pin connector you either split it in 2 (if it's designed to do that) or just put it on and let it overhang (as only one half of it will fit the 4 pin).
If you force it then it'll fit anyway but by design it'll just fit on.

The computer will run backwards

What I was working at the DHSS, we had a network of small calculator sized machines around the offices, and a main BT Merlin acting as a server. The calculator sized machines plugged into the network using a D connector. A very definitely shaped one too. I to,d one of the managers that there was no way you could plug it in upside down after she said she was concerned it could happen.

Two days later: she managed JUST THAT. I have no idea how. It must have talked a lot of force to get it to go in. Obviously the plug and socket were knackered and they had to get someone into fit new ones. A memo went round reminding us not to unplug stuff like that.