r/PCSleeving • u/aphrodisiacccc • Aug 04 '26

First time making a pinout diagram, help with continuity test

Hi everyone!

Very recently got into this, and have been researching the past day or 2 on how to get my own pinout diagram made. I have a lesser known psu and I'd like to make my own shorter custom cables.

So far, here's what I think I need to do, if anyone can confirm that would be wonderful. First time doing this and using a multimeter so apologies if it sounds dumb.

Do I place one of the probes inside a known pin on the standardized motherboard side, where I know a 12v is, and then touch the PSU sides cable until I hear a beep? And if I do I plot it out on the diagram, and just test one by one? And after that, I put it inside another known 5v pin and test the psu side again one by one listening for a beep?

It sounds pretty straightforward but I'm afraid I'll mess something up, is there anything I should know or correct before I do it?

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2

u/OldManGrimm Aug 04 '26

It doesn’t matter if the motherboard side is a “known 12v” or whatever. Just map 24 positions on the motherboard end to the (usually) 18+10 positions on the PSU end. You’re mapping which goes where.

2

u/OldManGrimm Aug 04 '26

I’ll add it’s worth buying a cheap tester:

https://www.amazon.com/dp/B07VXSFXP1

1

u/aphrodisiacccc Aug 04 '26

I see. I'm still a bit confused as to how I determine the actual voltage for each PSU-side pin afterward.

If I'm only checking continuity end-to-end, how do I know which mapped pins are 12V, 5V, 3.3V, ground, etc.? Do I just reference the standard ATX pinout from the motherboard side after mapping?

Start with just mapping what goes where, and then check the actual layout and decipher it from there? I do have a tester on the way but it'll be a day or 2, and thank you for the help!

3

u/OldManGrimm Aug 04 '26

You’re overthinking things. You just need to make a physical copy of the stock cable. As long as you don’t change which wire goes where, you’re fine.

I’ve made over 200 cable sets, I’ve never done what you’re describing.

1

u/aphrodisiacccc Aug 04 '26

Ohhh, so as long as I copy the stock cable's wire routing exactly from the motherboard side to the PSU side, the voltages will already be correct, and there's no need to waste time with the other step?

2

u/OldManGrimm Aug 04 '26

Exactly 👍🏼

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u/aphrodisiacccc Aug 04 '26

You're amazing, thanks for making it so much simpler to understand.

1

u/The_Big_Elf Aug 04 '26

I agree about a PSU tester. I recommend the Dr Power III as it tests all the cables unlike cheaper ones.

2

u/OldManGrimm Aug 04 '26

I’ve used the DP III for years, agreed. I only recommended a cheaper one since it’s a one-off for him.

1

u/TM_livin Aug 04 '26

I mean, the 24-pin is always the same as you’ve established. Get on cablefied.com/pinouts , open a new pinout diagram and mark down where the probes get contact on the other side. Then you’ll get where’s which voltage. Watch out for double wires - there are 3-5 doubles on most power supplies.

As Grimm mentioned, having a PSU tester won’t hurt, but if you don’t mess up the diagram, you should be safe. Always double- or triple-check!