Batboard

I have two VHF Saber 1's. When I hook up a NMN6128 Speaker Mike I get no audio from the speaker mike. The mike and PTT seem to be working. When I use the Motorola RTX4005B Test Box, I do hear audio when the speaker out switch is in position "A". When I intsll the NMN6128 Speaker Mike on my several UHF Saber1's, I have no problems.

Anyone have any idea what the problem might be? By the way I took the VHF radio and put it in a UHF case and things worked fine. Might there be some option that I have missed to get this NMN6128 that has to be programmed on the VHF radios?
AAMSTER

By the way I took the VHF radio and put it in a UHF case and things worked fine.

You solved your own problem, the case is bad. There is a flex circuit in the case to route the speaker/mic to the radio. One (or more) trace(s) has got to be open.

Might want to think this one a bit closer. When test box is hooked up he has speaker audio in it. That would be somewhat indicative of traces
being good. Consider that the processor is not reading the voltage
set by the zener diode in the accessory properly. The way to confirm this
is with a different accessory which would have a different value or the
saber test fixture which allows you to select them. Dont think it could be a bad diode in the spk/mic due to the fact that it works ok on other radios.
Just some food for thought. Phrawg

He also said the VHF radio worked in the case of a UHF radio. The cases are the same, therefore a defective flex in the case.