Quote from: Elphamyto on August 22, 2017, 05:06:29 AM

My first guess would be that the 4-pin pci connector could be used to link other PSU's and activate all of them by turning on one. You could test this by checking for continuity between those 4 pci pins and the HP's contacts. If they connect to contacts 33 and 36 (and probably a ground pad) then that's likely what it's for.

There's no continuity between the 4-pins and any of the pads or 12v or ground of the PSU. The power switch is a 3 position switch too. Off-nothing-power. I've pinned them with all 3 switch positions as well. They only have continuity to each other within the 4-pin connector. I guess, I'll just have to experiment, or find documentation somewhere. Unfortunately I don't have any 4-pin PCI connectors laying around. It would be nice to know, for example, if the slave units get put on the middle position and get powered up as the others get powered up.