Pioneer AVIC F80DAB buttons do not work anymore

[sadibe]

Hello everybody

I have a Pioneer AVIC F80 DAB.

Compatible with a NEX.

Yesterday I wanted to attach a slide and I cleaned the display.

The LED on the buttons lit up all the possible colors.

Have the radio expanded and let dry.

Now it is so that when I press the volume minus button the bars become ever softer.

The Mode, Map and Eject buttons do not work at all.

Question: Can I open the device and clean / check the contacts on the buttons?

If so, how do I get to these buttons or how do I open the device?

Thank you very much for your help.

 

regards

Sandra