Coriasis

Would you happen to know how I could test if the ExpressCard port is working?

It's a bit of a mess but here: The PSU is plugged into a power strip not shown on the right. No lights appear to be on.

Yes, I have it connected to a working Fujitsu Lifebook A Series via an Expresscard slot. Tried again with another ATX PSU and that didn't work either.

You're right, I miscounted, it's 24 pins on the PE4C and 20 pins on the PSU. However, the card doesn't power up when I plug it in on the right. I've verified the PSU with the paperclip test and the adapter "works" when powered from the 12v jack(the charger doesn't have sufficient wattage for the card's TDP though). Is there something wrong with the cable or do I need a 20 to 24 converter?

Hoi, I bought a PE4C v3.0 recently and tried to connect an ATX PSU to it, but the white power input slot has holes for 24 while my PSU has only 20 pins on the connector. It only plugs in with flush with the right side, leaving 4 unfilled on the left. Is this adapter supposed to have that many pins on the ATX power slot? What is supposed to plug into it?