I have a Dell Dimension 3000. The plug for the DC power connector P7 came loose from the hard drive. I cannot plug it back into the space. It does not seem to fit because of the jumper, which is on the pins in the socket. I checked and the jumper is on the correct pins. What am I doing wrong? Is there a workaround that I can do with the data cables if I remove the jumper? the connector fits without the jumper, but it must have also fit before with the jumper because that is how the computer arrived about four years ago. The data cable and power plug (for the hard drive) fit fine.
There are only 2 cables that connect to the hard drive--power cable from the power supply and the data cable that connects from the drive to the motherboard. Nothing goes where the jumpers are--those are left exposed. Service Manual HERE. You might be trying to attach the end of the cable that goes on the motherboard.
edit--There are several loose power connectors that don't connect to anything. They are for expansion--adding new hardware.