|There's really nothing a picture will tell you that my eloquent words won't.|
You only need the 4-wire power and 40-pin data cable connected and those only fit one way The data cable is keyed by a missing pin and the molex power connector is beveled on each side so it can't be plugged in wrong, although I suppose you could plug it in upside down if you applied herculean force when inserting it.
The data cable will have a red stripe along one of its edges. That side of the cable needs to be connected to the # 1 pin side of both the drive and motherboard connections. Although, as I mentioned above, if you match the filled in hole of the cable with the missing pin of the drive then it will be connected correctly.
If the bios is no longer seeing the drive then it may well be bad. But there's a couple things you can check. Make sure the data cable is in good condition and tightly connected to both the drive and motherboard ends.
And sometimes the metal contacts in the molex power connector get flarred out and don't make good contact with the drive pins. Since most power supplies have a surplus of drive connectors you can try another one.