My fill 2 button is stuck when i press it.Anyone has a tutorial how to open the audya to see whats happening?

Try to look here:
http://www.ketron.it/images/ketron/manualiPdf/Espansione_web.pdf

Orla

The only problem I had was with the two screws under the keys that holds the end caps on either side. I had to use an L driver or flex drive to get at the screws.

I am just an average bungler and had no problems. The top lifts up and over, but it can't lay flat because of the ribbon, You just have to have something a little higher in back to support it open.

If you take out the right screws, nothing falls down or out.