Wonder if anyone can help shed some light on this.

Two days ago the Comand APS in my R320 CDI became non-controllable from the fascia buttons. None of them respond, and neither are they illuminated.

The Comand unit itself still seems to be functioning - radio, phone, etc all working, and the steering wheel controls are working. However, without being able to access the different menus, use soft buttons etc it is basically useless.

I tried pulling the fuse, but when it loaded back up it is just the same.

I also noticed while sitting in the car yesterday with the ignition off waiting for my daughter that every 20 seconds or so you would hear the navigation disk spinning up and then slowing down. It did this for the whole hour I was in the car with the key out of the ignition.

The car is currently being serviced by an Indi Merc specialist and they have never seen anything like it before. They've checked fault codes on STAR but don't see anything that could be related to Comand, and thus conclude it must be something internal to the unit.

Any thoughts?