@ rude1978 - Since the thing was most likely opened and, coming from eBay doesn't help matters any, had who knows what done to it, you're only real bet would be to have the drive looked at by someone to see if a key can be extracted from it, and even then it's no guarantee it's the right one, really depends on what was done to it, and you'll most likely never know what that actually was.
Take the 360 apart and remove the DVD drive and then turn it on, see if it works. If the drive is the only problem the 360 will start up and get to the dash just fine, but that only gets ya about 1/10th of the way there, if the key either is not on the drive or is the wrong one the best you'll get from it, even with a new DVD drive, will be a CD/DVD player, and since it's a right crappy DVD player it's pretty useless if that's the case. If the thing works fine with the drive removed, and you can get a key from the drive, and if that key is actually the one that's for that motherboard, then you'll be in pretty good shape, but if even a bit of the key is missing or not even there at all, then it's pretty much just good for parts.
PM me if ya remove the drive and the 360 works, I can remove the FW chip from the DVD drive and dump it to see if a key is there, and/or what the problem with the drive may be.