it might be needing flash updated though i would be very careful , this cannot be erased unless it is possible to flash back to an earlier flash version.
Did they say anything bad about it when you got it back from the shop?
is it just that disc or are they all not working?
if it is on the same IDE then youll need to use the DVD as master and everything else as slave...
you can set that inside the pc using the jumpers (plasic thingies
) on the pins on the back of the device
it will tell you either on the device or in the manual what you need to do to ensure you have the right one selected!