Batboard

I have a GM300 that up until about 4 hours ago worked perfectly, I was using it earlier today to Tx and Rx with absolutely no problems, I picked up my mic went to transmit and guess what nothing no red light no repeater static. tried transmitting to it from a handheld and still nothing, also tried it on my simplex channel with the same results. If anybody can give me suggestions or can fill me in on what the problem could be. Thanks

GM300's have problems with the interconnect plug.
The feedthru capacitors on the interconnect plug break and the radio goes "out to lunch".

I'd check the feedthru, but there may be more to it than that, the feedthru doesn't generally stop the radio from keying..

I'm not sure what a feed through is, if it isn't that what could it be, it powers the LED on the mic and I can read it so I don't think it's the plug.

The feedthrough is the connector that goes between the RF and Logic boards in the radio, if you do a forum search you should come up with more info on them.

Instead of calling that part a 'feedthrough', I'd suggest calling it an interconnect as it interconnects the RF board to the logic board and vice-versa.

It's the only multi-pin connection between both boards, and is a common problematic area as well.

Oxides coat the pins and you get erratic noises on TX as well as 'disappearing' audio on both TX and RX.

Order a new set, both pins and receptacle and you should be far better off than trying to clean them, or bend pins and sockets about willy-nilly.

I built a test adaptor just for this purpose years ago....to remotely test the boards outside of the radio's frame.

Every erratic sound I heard and saw on the scope was derived from that multi-pin interconnect.....

AEC wrote:Instead of calling that part a 'feedthrough', I'd suggest calling it an interconnect as it interconnects the RF board to the logic board and vice-versa.

You might want to take that up with Motorola, as they call it a "CONNECTOR, FEEDTHRU 14P"
and yes, they spell it with a "u" instead of "ough".

Take the logic board out to get to it, if the part number stamped on the connector is not 2804637J01 it's one of the older style ones that breaks and should be replaced. You shouldn't need to replace the sockets.

jackhackett wrote:

AEC wrote:Instead of calling that part a 'feedthrough', I'd suggest calling it an interconnect as it interconnects the RF board to the logic board and vice-versa.

You might want to take that up with Motorola, as they call it a "CONNECTOR, FEEDTHRU 14P"
and yes, they spell it with a "u" instead of "ough".

Take the logic board out to get to it, if the part number stamped on the connector is not 2804637J01 it's one of the older style ones that breaks and should be replaced. You shouldn't need to replace the sockets.

I think I'll pass trying to convince Circle-M to print the proper terminology in their documents, I don't think they would understand anyway.
After all, they DID move the service facility to Mexico......'Nuff said!