Power Supply Better understanding PSU pinouts for custom cabling

Tuscany

Cable-Tie Ninja
Original poster
Apr 26, 2020
159
63
So, after going some back and forth, I decided that I will go full custom cables for my first SFF build.
The PSU of choice is straight-forward - Corsair SF600. Last time I did a sanity check I had just one left hand, so I don't have any big concerns. I watched couple of videos, got pinout diagram (there is one here in the forum as well).
What I need is confirmation of my thoughts so I know I have a better understanding of what I do, instead of following blindly.

1. All mainstream PSUs have the same pinout on the side of the motherboard - the ATX 2.x Standard:

So, whatever I do I need to get pins 16 and 17 right so I can measure the rest with multimeter and before I plug into the MB, I need to verify the picture above (same applies for 8/6 pins but I guess they will be easier to follow).

My question at this point is - how do I measure what comes out of the PSU at the PSU? Again, there are diagrams here on SFF, but how do I get the pinout myself?
1. Do I track the green and the black from the MB connector to PSU connector and then paper clip them onside the female connectors at the PSU and do the measuring with multimeter, without any cables whatsoever? Not that I have the urge to do this, but I want to understand what I do better.
2. Or the PSU should be opened and the cables must be checked on the inside? Which I am not doing anyways.
3. What reading should I expect from blue and gray wires? Do I also measure them with the 20v as well?

Thanks in advance for any input :)