What power connector? The photo isn't clear enough - I just see some black blobs on a circuit board. You'll need better lighting and contrast - you might be able to enhance the image with a Photoshop-like program.
It's circled here, right next to the SATA connector. It has slots for four pins, but only has two full sized pins and on the far left in the pic a half sized pin.
It's a dell latop IDE to SATA/PATA board/carriage (YG544), which I've googled, but for the life of me can't find out anything about the power connector itself. It seems to be something associated w/ the Optiplex 740/745 series, but for the life of me I can't find anything on what the name of that power(?) connector is or where I can find male versions of it.