NJ Locksmith Buzzer Wiring 

Picture
The Buzzer Wiring
NJ Intercom repair.Nj Buzzer Replace Nj Intercom Fix
This should be your final culprit before you call in the experts.
NJ Intercom repair.Nj Buzzer Replace Nj Intercom Fix
Inspect the wiring underneath the chime covering. 
NJ Intercom repair.Nj Buzzer Replace Nj Intercom Fix
Use the screwdriver and electrical tape to tighten any loose wiring and repair the damaged ones. 
NJ Intercom repair.Nj Buzzer Replace Nj Intercom Fix
Now test for voltage using the voltmeter. 

NJ Intercom repair.Nj Buzzer Replace Nj Intercom Fix
If the readings are below 6V or above 16V, then you will need to replace the chimes themselves.
NJ Intercom repair.Nj Buzzer Replace Nj Intercom Fix