Originally Posted by bwca44
Hello all- recently I have had two moto PMMN4039A speaker misc that will transmit when connected to the ht1250/750 but will receive no audio. I have ruled out the radios as being the issue...both of these mics were very gently used, all pins are intact and extended
If I'm not mistaken, that mike has an audio jack that you can plug a little earpiece into. Maybe rust, dirt, or cosmic dust has corroded or caused a bad connection on that. Get a 3.5mm jack and plug and unplug it a few times and see if it brings it back. If it does, cut the end off a Q-tip, soak the end in a little alcohol, (not Maker's Mark), and stick the cut end in there and try to clean it out. You could also just put alcohol on the end of the 3.5mm jack, but I do it the first way.
If that don't rectify it, identify which pin on the mike connector is the speaker, and ring it out, see what you get. Should be somewhere between 6 and 12 ohms. If it's shorted or open, get a new mike.