I recently purchased a 2011 LS460 with the Mark Levinson audio system. AM and FM radio and MP3 on USB plays, but it will not play CDs or DVDs. They load and unload ok, but no track info or song titles appear. I assumed the head unit was bad and ordered a used one from a salvage company. The replacement has the exact same problems. While it is possible the salvaged unit has the same faults, it does not seem likely.

It is my understanding that the disc player output is via fiber optics. Therefore the fiber optic part of the power amplifier could be faulty. But wouldn't the head unit still "play" the disc (track info and song titles, etc,)? Any help troubleshooting will be appreciated.