What to check

Check the door panel microphone hole (found at the lower-left corner of the Entryphone logo) is clear.

Corrective Action

Clear the microphone hole taking particular care not to push the debris further into the unit.

Additional notes

With polished brass panels, there can be a build-up of metal polish and it may be prudent to unmount the loudspeaker assembly to clear the debris more effectively.

Links

Spare for microphone:

https://www.entryphone.co.uk/shop/productdetail/ETXAMP-MIC