I have a 2000 E320 Wagon with a fiber optic CD Changer. I have a the standard deck, not COMAND.

When I press CD on the deck, it responds with:
"No CD Changer"

The CD Changer is powered and connected. It accepts and ejects the CD magazine.

Did my CD Changer go bad? That's what my local MB dealer thinks and they'll sell me a new changer but won't guarantee that it'll work. And to troubleshoot, they want to charge me $60/hr.