gm300 issue

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Irishfirepics
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gm300 issue

Post by Irishfirepics »

Hi I'm having a problem with my gm300. I was given 2 and one works fine. The other is not tx or rx I'm not getting any tx or rx lights Either. I noticed on the one that's working there are no jumpers crossed at the back. On the one that's not working jumper 15+16 are connected and 7+9 are connected. If I remove the jumpers I lose the internal speaker and still no tx or rx. Any help would be great.
Jim202
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Joined: Sun Sep 09, 2001 4:00 pm

Re: gm300 issue

Post by Jim202 »

Irishfirepics wrote:Hi I'm having a problem with my gm300. I was given 2 and one works fine. The other is not tx or rx I'm not getting any tx or rx lights Either. I noticed on the one that's working there are no jumpers crossed at the back. On the one that's not working jumper 15+16 are connected and 7+9 are connected. If I remove the jumpers I lose the internal speaker and still no tx or rx. Any help would be great.



The first thing I would try to do is read the radio. You have no idea if both radios are programmed the same.

Your kind of taking a pig in a poke here. Are the radio model numbers even the same?

If they are the same model numbers, then you might want to try cloning the good one to the bad one.

There is just so many unknown's with the limited information you have provided, that any real help anyone might provide would be pointless.

Jim
Satelite
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Re: gm300 issue

Post by Satelite »

Hello:
I wish you would have just mentioned the non working radios symptoms as the way you describe the working versus non working sorta confuses me.
But ill take a stab at the no tx or rx lights as in radio does not even power up.
If so you may have a radio that was setup for ignition sense control.
If so putting 12 volts dc power to pin 10 on the 16 pin option jack should power up the radio.
Or the fuse on the logic bd has blown open and needs radio checked out and the fuse resoldered back in.
You did say a 16 pin bd by jumper configuration so if that's correct id say the fuse is marked on the bd as F801 and is behind the pin 1 option connector positioned front to back and usualy green in coler looks similar to a resister.
Its refered to as a pico fuse and rated at 2 amps.
Also radio should power up with out the jumpers on the back and as you already found out 15 to 16 jumper is the radios rx audio but if setup for ignition sense youd need 12 volts dc on pin 10.
Satelite
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jackhackett
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Re: gm300 issue

Post by jackhackett »

As for the accessory plug jumpers, that is the normal configuration that comes with the radio, 15 & 16 jumped for internal speaker, 7 is ground and 9 is emergency input, if you programmed the radio for emergency you would remove the jumper and connect a normally closed switch in it's place.

So nothing out of the ordinary there.

I'm going to say the ignition sense isn't the problem, since you said you lose internal speaker with the jumper out... which means the radio must be powering up.

Now, you say you're not getting TX and RX lights. Are you getting a channel display? Mon or Scan light? Beeps when you push the buttons? If you hold the Mon button down for several seconds do you get squelch noise?
Irishfirepics
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Re: gm300 issue

Post by Irishfirepics »

Hi

sorry for the poor info.
heres what i get with the non functioning radio.

it powers up fine
I have a display
i hear tones when i press the monitor button etc...
the amber monitor light is illuminated
when i press the ptt on the mic i get no tx light nor am i able to hear any transmission on a hand portable tuned to the same frequency
when I transmit from the hand portable radio the gm300 does not receive the transmission

I have read the radio on the rss and it reads fine, I cloned a working gm300 to the non functioning one. it seemed to clone fine, no errors and I have the correct amount of channels on it.

still no tr or rx
Irishfirepics
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Re: gm300 issue

Post by Irishfirepics »

Hi
sorry for the poor information

my last post didnt post, I'll give more info now.

the radio powers on ok
I have a display
i hear sounds when I press any of the buttons like the monitor
there is an amber light on the monitor

when i press the ptt on the mic, i get no tx light nor does a hand portable tuned to the same frequency receive any transmission
when i transmit from the hand portable i do not receive anything on the gm300

I have 2 gm300's, one works perfect, I cloned the good on onto the one that is not working and it made no difference.
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jackhackett
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Re: gm300 issue

Post by jackhackett »

One possibility is that it could be a synthesizer out of lock problem.
The feedthru connector between the RF and logic boards are known to go bad, that can cause all sorts of problems. Do a forum search for gm300 feedthru, it's been discussed here numerous times.

Sounds like the radio going to need some troubleshooting at the circuit board level.
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tsunami_australia
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What radios do you own?: too many to list here apparent

Re: gm300 issue

Post by tsunami_australia »

Sounds like it may possibly be out of tune? Not sure how similar they are at the butt but I had a GM339 that went deaf and dumb, turned out to be a solder issue and re-soldering the antenna socket and a few other spots instantly fixed the issue.

As for the rear connector, two of them were loopback for the front speaker (I thought it was 7&8 but been a whilst). I just used a motherboard jumper off an old P2/P3 motherboard to jump the speaker but that won't affect the tx nor the rx light.

As suggested, check in the RSS for ignition sense options. Shouldn't affect rx though I don't think but I've not fiddled with IS on the radius, only Jedi, Odysea and Simoco SRM9000s.

FWIW I had a GM300 arrive here that would TX fine but would not RX. It was to be put to a repeater pair as the tx'r being a 40w edition. There was no reason found for the lack of rx unfortunately.
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