Newly Installed Dvdrom As Secondary Drive Is Not Found By Computer?

I recently bought a dvdrom (asus) and tried to install it as secondary drive(as slave to my burner)but my computer is saying secondary drive(1) not found.
what seems to be the problem?
the cables are okay. udma is on.
the cable is 40 pin.
its an asus dvdrom.
thanks.

When you power on the unit, does the drive tray open when you push the eject button?

Assuming the jumpers are set properly, try the drive on the other IDE channel if possible. Also try a different cable, just to be certain the cable isn’t the problem.