i bought 3 of these off your ebay, magicgrow...etc etc. i can't seem to get them to work, tried all 3. i plugged in molex, molex is attached to hard drive and psu. gpu isn't recognized in device manager. if i directly hook up gpu to mobo, it works. when i attach to your cable/card, gpu isn't recognized. help!

corsair 1200ax
12gb ddr3
amd fx 4400
2 @ xfx r9 270x
1@ xfx r9 290
asrock extreme 4 970 mobo