SONY XR-C450RDS - Help please
 

I have recently had my car at the local garage and they have had to
dismantly the dashboard to replace my heater matrix. On return of the
car something odd had happened to the controls of my car radio.

I am using the XR-C450RDS with cd changer CDX-605. I have a steering
column remote.

When I pressed volume up the radio was a maximum volume, when i press
volume down the unit goes to mute mode. I press mute and nothing
happens.

The system is a good 6 years old and the LCD display has already lost
its 'glow' and is very faint.

Is this something simple and obvious that I can fix without returning
the car to the garage?

Any help would be apprectiated.

Thanks