I haven't seen one of these machines in decades but upon initially powering up did it used to rotate the carousel to quickly asses which disc slots were loaded? If it did do that but no longer, perhaps it needs some manual help to rotate the carousel because its motors are week or there is an object causing a jam which you can dislodge?
I've seen old CD players where they won't spin however if you help out
manually and start their rotation with your fingers as a "kick start "
they then work! [For that play at least.]
UPDATE: Usually problems are common ailments so checking out what others with this machine are saying may help.
Not your exact unit but perhaps of interest: