Blaupunkt Stereo Problem With Blaupunkt 520 Car Stereo In Holden Astra?

Problem with Blaupunkt 520 Car Stereo in Holden Astra? - blaupunkt stereo

I installed a problem with my car radio Blaupunkt 520 in Holden Astra car.

The stereo was factory installed and are currently at least 6 years old.

There is a problem with volume control. If you are later, the radio volume to 100% (damage) my speakers. I turned on the radio manually to zero before it is out of my car, next time I go to my car back to 100% vol. This problem occurred a few weeks ago and is now a problem.

Can someone please help me.

PS. We have tried to restore the stereo without result.