I have had for a little while. on my 2004 L322 The radio doesn't play any sound all of the features worked until today, now only the main menus work and the TV but still no volume. I have checked the back boot for water ingress but cant see anything. I suspect it could be one of the main components. I have also checked all of the fuse even the one under the plug. The power light will some times switch on or off but takes a while.
Any help would be greatly received if any body has had a similar problem.

I had this early on, l took the 3 plugs off the top of the dsp in turn and found it was a bad connection on the plug nearest the centre of the car. Cleaned with contact cleaner, been ok ever since. Worth a try

If that doesn’t work l would suspect corrosion in the dsp itself. The socket pins have been known to corrode and disconnect.

Thank you I will have a look.