Power Supply voltage test

@wattmagner you are correct 4 wires on the left in your orientation are negative1; 4 from the right are positive the center wire is not connected.

@oldturkey03 / @wattmagner - your multimeter 1 probe contacted 1 wire/contact in the (red text group/above image) and the other 2nd probe contacted 1 wire/contact in the (white text group/above image)?

if one probe accidentally touched two contacts at once (in white or red group) would that short out the PSU? a friend with some electrical background said i have to find a ground for one probe then ONLY touch ONE contact say in the red group. if i accidentally touched two red group pins would could short out PSU.

do u have a technique to touch only one pin?

thank you!

@rasberry it is of course always a bad idea to cross points but I do not see how or why it would shorten things out. Anyhow, the pitch between the contacts is wide enough to really not worry to much about it. Your probes should not be that thick. If they are, use smaller probes. Always good to have a variety of test probes for your meter.

Thanks for this valuable information. I was able to determine all 4 pins were delivering 12VDC nominal. but my Mac mini still won't power up. I followed the recommendations to swap out the SSDRAM ( no help), test the battery (2.78vdc0 and test the power with (also no help). I'm wondering if there is additional troubleshooting recommendations or a way to load test the power supply. thanks again