GM300- No audio

bleazenb · Post by **bleazenb** » Mon Mar 11, 2002 5:03 pm

Can anyone tell me why I can not get any audio out put from a UHF GM300 mobile radio. The access. shorting plug is pluged into the back. Even with an external speaker there is no audio. This radio was part of a UHF RF-Link system and was used for a transmitter only. Is there some jumper internal that Motorola techs could have used to shut off all audio output?? This is driving me nuts trying to figure this one out!!

Nand · Post by **Nand** » Mon Mar 11, 2002 5:14 pm

bleazenb · Post by **bleazenb** » Mon Mar 11, 2002 5:36 pm

Thanks for the quick reply. Yes the TX/Busy light does flash when it is receiving. And No the power up beep is not there. No audio what so ever. Any ideas?

Alan · Post by **Alan** » Mon Mar 11, 2002 5:48 pm

Is there Rx. audio on the mic. jack (forget which pin).
If yes then either
1) it may be programmed for handset operation (no speaker audio when the mic is off hook).
2) Audio amp blown. This is common as the speaker leads on this radio are floating (short any lead to ground and poof).

Do some trouble shooting with an audio tracer.

bleazenb · Post by **bleazenb** » Mon Mar 11, 2002 5:55 pm

Alan Thanks I think you found it. I traced it back to the audio amp and it indeed has a pin hole blown in it! Now the question, where can I get a new one and what Motorola part Number is it, if I have to order it from Motorola? Thanks for all the help!

Will · Post by **Will** » Mon Mar 11, 2002 8:26 pm

Some time when radios are used in Links, Repeaters they are modified to shut off the audio amplifier stages to conserve battery power at the site. Just another hint to look for, in case that problem comes up.