2002 E320 radio controls don't work
 

Hi all,

A colleague of mine just purchased a 2002 E320 and told me she is having a problem with the radio. The radio works, the display works, even the display on the dash shows the radio station, but none of the buttons on it work. However; the volume buttons on the steering wheel work. I am new to working on MBs, so I need any guidance you can give me.

I have been searching for the past couple of days, and can't seem to find anyone who posted about a similar problem.

Thank you :)