Pins 16 and 17 for a 24-pin ATX main power cable connector, and Pins 14 and 15 for a 20-pin ATX main power cable connector.
1) 24-pin ATX main power cable and it's respective connector,http://www.playtool.com/pages/psuconnectors/connectors.html#atxmain24
2) 20-pin ATX main power cable and it's respective connector,http://www.playtool.com/pages/psuconnectors/connectors.html#atxmain20
Just remember; The Green wire is the Soft Power On wire, (PS_ON)
ANY Black wire is a Ground wire.
A jumper wire is used briefly to touch the green wire to ANY black wire.
The preferred jumper wire is a paper clip because of it's size. (Diameter)
The jumper wire goes down into the BACK of the connector, RIGHT NEXT TO THE EXISTING WIRE that is already in there.
The BACK of the connector is where the wires go in. (In the links above look at the photo to the far right)
The 24-pin, or 20-pin ATX main power cable, is plugged into the motherboard.
The Power Supply is plugged into power.
The jumper wire goes down into the socket hole, right next to the existing wire, and far down in the socket hole.
It has to touch a metal terminal that is in the FRONT of the connector.
Each wire going into that connector has a metal terminal at the end of it.
Black plastic electrical tape is wound around the middle of the U shaped paper clip.
Use the jumper wire and the Power Supply comes on?
You have a bad Power On switch.
Power Supply does Not come on?
You have a bad Power Supply