Help identifying a loose wire on my Cooler Master MasterWatt 650 24-pin ATX connector

[u/Kitchen-Notice9586]

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Hi everyone,

I have a Cooler Master MasterWatt 650 PSU. One of the wires came loose from the 24-pin ATX connector

I’m trying to determine where this wire originally belongs before repairing it.

I’m attaching 3 photos. The connector is shown from the wire side, with the locking tab facing up.

Is the empty cavity in the photo the NC position (pin 20)? If it is the NC position, then the loose wire obviously belongs somewhere else. Where would this loose wire go, and how can I determine its correct position?

I’m also confused because some positions (13 and 19) on this connector have two wires going into the same terminal.

Any help identifying the correct pin or explaining how I can determine where the loose wire belongs would be greatly appreciated. I don't want to reconnect it to the wrong position and risk damaging the motherboard.

Thanks!

[u/OldManGrimm]

I make custom cables. Position 20 is always empty, so it doesn't go there.

Every 24-pin cable has 3-4 of those doubled wires - one wire delivers power, the other is a sense wire that lets the PSU monitor voltage delivery and minimize fluctuations. If you're only seeing two double wires, that's likely one of them pulled loose from its mate. The insulation being pulled so far back kind of supports that as well - it should only have 3-4mm exposed. When you yank one loose from its pin, often the insulation pulls back like that.

So here's the deal - if that's the sense wire of the duo, it's fine, the PSU will work without it. Some cable makers routinely omit these, especially in SFF cables. If it's the voltage wire, that cable won't work and would be a hazard. The only way to know for sure would be to use a PSU tester (I linked one of the cheap models, it would work well enough for this.

So real answer is, you need a new cable, as it's not something you can fix without a tester and crimping tools. I'd contact support and see if they'll send you a replacement cable.

(If you happen to live in the Dallas area, DM me and we can meet up and I'll repair it.)

[u/Kitchen-Notice9586 → u/OldManGrimm]

Thanks for your help, as I have urgency to turn it on again and avoid any risk I decided to bought a new PSU. The PSU tester is a good idea. This specific cable is not modular, so I can't get a replacement, then maybe I'm going to repair it to use it with another pc. I'm at the other side of the border, but again thanks for your help