Availability of BTicino parts.
As you will be aware the older Terraneo/Bticino 2000 series modules and components are definitely no longer available. Even the good old 600 handset is no longer available. The only part that we can still get is the 2659 speech amplifier. But for how long? We do not know at this stage.
You have probably been experiencing difficulties lately in obtaining some spares. Many of the 8 wire / 5 wire modules are no longer available. Many of the "monoblock" panels are also no longer available. In the 2 wire range the problem is not so severe and 2 wire modules can be obtained but the cover plates are not readily available.
Sadly it may well be time to consider replacing rather than repairing systems that are out there. This range is well on its way to being obsolete. It would not be ethical to replace a part only to have to tell the customer shortly after that further parts are no longer available.