Someone with hands on experience should be a long soon.
But I'll have a crack at it from an electronics technician
point of view.
1) You have checked that they all don't work. People may think they are faulty when it is actually their operating.
Check the volume control settings.
2) Get a known good ( working )
headset and pack. Label both of them so you know the good ones. Once you put it down on the bench it is easy to forget which one is the god one.
3) After checking for any visble faults such as damaged connectors
etc try the
unit ( pack /
headset ) your testing with the appropriate good
unit. Then note down any obvious faults eg the
call light won't lightup when called from another good
unit on the
system. Does the
call button on the faulty
unit operate the
call light on the good
system?
With a good
headset on the faulty
unit can you hear the difference when the mike
switch is turned on / off ?
On a faulty
headset check whether you can hear someone and whether they can hear you. Headsets are more likely to be broken wires in the leads / connectors.
Now you have worked through all the headsets / belt packs you should have a list of faults.
Now using different ones you maybe able to isolate the faults more.
For instance if a
call light doesn't work it could be the
bulb so you could try swapping out a
bulb from a faulty
unit the
call light works on.
I don't know what
level of skill you have with electronics but if you are happy working on electronic circuits you could use a multimeter. With a good
unit connected up with the faulty
unit also connected do a side by side comparision of
voltage levels. Starting at the connectors working back to the
PCB.
If the
PCB's are wired to the the
call light/ switches/ audio connectors using plugs instead of wires soldered directly to the
PCB then you maybe able to swap a good
PCB so you can work out if it is the
PCB or the switches / connectors
etc that are faulty.
At a community college there should be some on-site technicans who might help you with this.
I am sure someone will be along with the most common faults soon. It would be a help to have the exact model numbers.
This pages has some pinouts for the
clear-com system, you may have to dig a little as this whole pages has to do with intercoms.
ePanorama.net - Links
Hope this gives you some ideas.