Found out that Dell power supplies have a secret pinout difference

I was swapping a PSU on an OptiPlex 7050 last Tuesday and grabbed one from my pile of spares. Plugged it in, system wouldn't even POST. Started testing voltages with my multimeter and found pin 13 on the 24-pin connector was reading different than the manual said. Turns out Dell uses a slightly different wiring standard on some of their proprietary boards. I found this out by digging through a forum post from 2016 on badcaps.net. Now I keep a printout of the pinout chart taped inside my tool bag. Has anyone else run into this with HP or Lenovo desktops?

3 comments

3 Comments

harperr8215d ago

I read Dell's pin 13 is actually a separate power good signal, same as what @abby_cooper saw on those Lenovos.

abby_cooper15d ago

I've seen this exact problem with some Lenovo ThinkCentre models from around 2018. They use a custom pinout on the front panel header that's nothing like the standard Intel spec. Had to rewire a new case once because of it.

young.ryan15d ago

The pin 13 thing is a real headache. I had a 7050 refuse to boot with a standard ATX supply once and chased my tail for hours. @abby_cooper is right about the ThinkCentres too, had a 2017 M715q that wouldn't power up with a generic front panel cable. Best trick is to keep a spare known-good Dell PSU around just for testing, and mark your spares with a sharpie if they came from a proprietary board. That badcaps.net thread is a lifesaver, I still reference it sometimes.