Batboard

Hi

Having problems 1 more time.
Some days ago, have repaired a GM-300 soldering a Pico fuse 2A, because of a bad connection on the back of the radio, with TX - RX repeater cable, just now realised the other radio was death to ! Wasn't light on, now is, did the same, fitted a new Pico 2A fuse. And radio now is lightning up fine, making the usual beep, when turned ON, it TX fine to, and RX to, because the RED led flash when is receiving, BUT NO SOUND ON SPEAKER, only the beeps when turned ON or when pressing buttons, even pressing MON button, the red led flash, but no sound after the beep!
In the back the jumper connector is fine, in fact already tested it in other radio.
Can anyone help ?

thanks

Swap front panels between radios to see if it is just the speaker. Or put an external speaker on as test. You should also check to ensure the jumpers on the logic board are still intact. One in particular (I do not have the schematic in front of me) - I want to say JU251 - in the detected audio path through the low and high pass filters to the vol control top - could have come out, leaving you with no audio input to the amplifier. You will need to consult a schematic.

the volume works, the speaker is fine, the beep sound when turning ON is ok. ill check the jumpers

its not the jumpers !

Ah. Missed the part about the power on beep. I would check the interconnect pins between the rf and logic board, and then go through the audio chain.

Hello:
Check in the rss programming of the radio in qestion and see if by chance it got its programming changed from palm mike to headset .
Also confirm in rss programming that radios are programmed for repeater mode and not conventional mode while your at it.
Funny things happen during a down right shorted circuit.
Id also check to see if the radio is set for repeater rx and not repeater tx .
Did you by accident get the GM300 mobiles swapped around for example GM300 that should be rx is in the tx radios position and vice versa ?
Also try holding down the monitor button and see if you get white noise sqeulch sound.
You must hold the monitor button pressed down for a few seconds to do this test.
When you do this = does the speaker produce sqeulch sound or does the activity light flash only ?
Check these out and post back.
Then ill probably have a direction of travel picked out to help remedy the problem.
Satelite

Ok, thanks for answer

Its not the headset, if we switch to headset, we can´t ear the beep to. And the beeps are very HI and strong.
About change to repeater mode, nothing happen, still the same. And it is the RX. But have the jumpers in the back, and theyr working fine in others radios, so its seted to radio MOD, still the same.
YES MY ERROR WAS THAT !!!!!!!!!!!
When i connected a new repeater cable from ebay, did wrong, the TX in RX and the RX in the TX, since than, was death, antil i change the pico fuse 2A, i alredy changed the xtal oscilator 44645mhz, and its its doing RX, but no sound, just the good beeps
Holding the MON button, the red start flash in did, but no sound, of open squelch!

thanks

Hello :
From the answers you gave me of the above qestions .
OUCH is coming to mind.
Although not the big OUCH
Since you are getting good alert beep on power up its not going to be the audio amp.
Are you certain your not being blocked on the sqeulch noise by a private line code or digital pl code ?
If your wondering then remove the mike cord from the front of the radio and try the monitor hold press down test again and see if you get sqeulch or not.
Otherwise im going to have to side with Bill_G and inform you to work through the mobiles rx audio circuitry to locate the trouble.
Unfortanately in the GM300 repair manual that i have there is no trouble flow sheet for you to work from.
Its schematics and diagrams that you work from at this point.
Start at the speaker and check on bd copper circuit paths - any burnt open traces ?
You already swapped fronts with same problem so id asume speaker is good.
And with good alert beep on power up it would seem to me the entire rx audio circuitry should be in fact good.
Gotta be a PL tone or DPL code blocking you and giving you the idea the audio is not there when it is in fact present but blocked by one of them.
Double check audio sqeulch test with mike cord unplugged from radio.
Also check in radios programming that it is NOT programmed for PL or DPL operation engaged with mike off hook .
Let me know what you find.
Satelite

Hi many thanks again for your time!

Got news. I changed the crystal 44.645 mhz again, i do have some lol ,,,and guess what, now the radio got sound of RX, but Pressing MON still´s not having squelch open sound at all ! About the CODES, it already programmed channels full open for RX and TX, no tones at all. Mabe now it´s more easy for you to avaliate the malfunction, since now its receiving, just not opening the squelch pressing the MON button.
What you think ?

I know how to reinitialize the board, mabe i should try it!

OK Satelite

It´s done, Blanked the board, reinitialize it, and then inject the cod plug i had in a floppy disk. It´s working real fine, the squelch open in MON button in any Channel, even with Tones ON
many thanks for your time.
,,like i already said, your grate in this forum, are the most from this forum, from UK or from where, you for example ?

thanks