thanks Ron,


yes I realized that I didn't have to unscrew the handset plastic face with Andy's picture and when he gave me a standard allen key size, since the cover is fixed by star shape screws.
Anyway, the problem is not coming from the button, but from the inside of the handset, Leon told me it is probably the magnetic reed switch.
The head is already on its way the be repaired.
I must say that Leon provide me a great service, he is making what could be possible to repair it asap.
I will let you know when I will have the final report.

Johnny