Thanks, I already have a manual. It doesn't specifically explain how the microphones work. It says that the microphone does not work unless the MIC button is flashing.
I understand that the speakerphone has the add-on module, with that, I can make it's MIC button flash, without it, I cannot.
Anyway, I'll have to set up a test one on our bench.

One of the other things the customer is complaining about is, "people cannot hear us unless we speak directly into the handset, If I have the handset on my shoulder, with the receiver below my chin, they can't hear me."
eeeeee-yup.

Last edited by NotNotCity42; 09/16/14 08:40 AM.