In this post I am going to explain making the power adaptor that is going to convert a 5 wire sata cable from the pc into the 12 wire power plug that is used to power a native xbox 360 DVD drive.
Above is a picture of the power leads depending on your soldering skills you have 3 option.
1 you cold remove a female sata power socket from an old HDD or DVD drive and make a lead from that which if you don't have much soldering experience then would be difficult. or
2 you could remove one of your male sockets off of the sata power lead on the psx of your pc and solder directly to the wires which is easy but the downside is it cant be removed.
3 if you don't want to make one you could buy one there not expensive but the downside is the switch to eject button is on the adaptor so if you want an eject button at the front of your case you would need to solder one to the adaptor. you can buy them from here.
using the pin-up above should be strait forward to make your adaptor the only think you must make shore is to use a switch (not a button) for the eject button for the dvd drive to stay closed it must be connected to ground and disconnected to eject.
after you have your power adaptor you need to flash the firmware on the drive to the 0800 firmware i am not going to be covering this in this guide as there are so many different drives and guides around if you need a guide try looking around xboxscene tutorial section for your model of drive.
in-order to flash a xbox drive not all sata controllers are compatible in my experience i have being using a via6421 pci controller works very well and you can pick one up for $30 aus on ebay very cheep
hope this info helps thanks for reading.