Modular PSU Cable Pinout

[Fuganater]

Anyone have a site for modular PSU cable pinouts? I found this site for the ATX power but idk if its right.

Help is appreciated as always.
-Fuga

[diluzio91]

if the cables are still in the connectors you can cheat, and follow the wires, the ends that plug into the components have to be standard, so look for standard pinouts, and trace them back, then make yourself a sheet with the 12, 7, 5, and ground pins mapped out. the psu's are (almost) all going to use propriatry connectors for the modular ends though.

[Konrad]

Connector pinouts are part of the ATX specifications, available online at www.formfactors.org and countless books and websites. You can even often find them in your mobo manual or PSU specifications. They are completely standardized across all consumer and enterprise PCs ... although beware a few infamous incidents in the past where Dell and HP changed their PSU and mobo pinouts to force proprietary dependence, so if you have a Dell or HP OEM unit (mobo or PSU) double check the connections before mixing and matching with non-OEM components.

Physical connectors (AMP, Molex, etc), contact pins, amp gauges and colour-coding of the wires are also clearly defined parts of these specifications. Black ground/return, yellow 12V, red 5V, orange 3.3V ... the other wires (purple, white, gray, blue, etc) on the mobo ATX12V connector sometimes vary ... pin 20 (-5V) is often absent on modern PSUs because "legacy free" systems do not require any -5V power to run ancient ISA/EISA/MCA/VL bus, phone modems, long serial cable runs, and similar junky stuff.

Having said that, there is no real standard for the modular connections on the PSU box itself, the ones where you plug the actual cables into it. Best to check all available documentation and trace the wires with a continuity checker to determine those pinouts - although I doubt that's much of an issue unless you're modding those cables or modding the PSU innards, and I suspect that they will tend to adhere to spec for colour coding.

[Fuganater]

I was afraid everyone would say trace them out. I didn't want to unsleeve the current cables. But if I have no choice then so be it I guess....

[diluzio91]

if they are still colored you can use the standard colors to help you trace?

[Fuganater]

Well not really. There are more than 1 black on every cable and the ATX is impossible. PCI-e cables have 3 black and 3 yellow. CPU power cable as 4 each. Kinda hard to figure out.

[Konrad]

Tracing the cables by physically following them is only one method. Electrical continuity checks can be made easily ... any ohmmeter will work, as will any cheap DMM with continuity/diode check functions, or even a battery and lightbulb. No need to unsleeve and sort a tangle or follow colours or whatever, just match the endpoints. The mobo/peripheral connectors have well documented pinouts, it should be easy to determine their counterparts on the PSU side if that's at all necessary.

[diluzio91]

and that is correct.... yellow is 12v, and black is ground. so any ground can connect to any ground... any12v can connect to any 12v....

[Konrad]

Assuming those Grounds and 12V lines are all on the same rail. You don't want to complicate load balancing, maximum wattage, and floating grounds across multiple rails ... it would just place more electrical stress on the PSU to shorten service life.