Ok, try this: I presume the motherboard has two IDE connectors on it. One is used for the hard drive(s) the primary, and the other for the DVD drives, the secondary IDE controller.
Try each DVD drive separately, one at a time on the secondary IDE controller. Be sure to set each to master when trying them individually. If this does not work, set each to slave and pair each one with the boot hard drive which should be connected to the primary IDE controller. If you can get either one to work as a slave with the hard drive as the master on the primary IDE controller, you may have a faulty secondary IDE controller.
If neither DVD drive will work on either of the IDE channels, I would borrow one from someone or buy a new one. They are relatively cheap and can be had for 30 bucks at some places.