GP300/P110 = Experts ???

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Satelite
Posts: 672
Joined: Sat Aug 12, 2006 10:43 am

GP300/P110 = Experts ???

Post by Satelite »

Hello:
Im here on my knees begging for help.
Ok heres the situation.
I got in a GP300 VHF 146/147 mhz 2ch portable.
The previous person used a speaker mike and has ruined the conections inside the jack for the speaker audio internal radio speaker.
It txs fine with and without the speaker mike.
It rxs with the speaker mike but without no audio is getting to the internal speaker.
So i get out my service manual and decide to bypass the adapter jack and run the audio to the speaker through the conector on the radio circuit bd to get into the flex strip to the speaker.
( Not going to use a speaker mike )
So i remove L405 and L406 and solder a jumper wire from the bottom of L405 circuits now empty space (Bottom of L405 is the furthest away from the adaptor jack) to the right side of C442 (C442 right side is the end facing inward towards the radios center)
Left C442 in the circuit to run audio through it to the speaker through the flex jack conection on the bd.
And i didnt get the audio bypassed as i thought id acomplish.
Anyone see what i did wrong or should have done to bypass the rx audio from the adaptor jack to the speaker.
Thank you.
Stumped Satelite :oops:
486dx4
Posts: 104
Joined: Thu Feb 09, 2006 4:56 am

Re: GP300/P110 = Experts ???

Post by 486dx4 »

I'm not an expert by any means but looking at the pinout/schematic for U409 which is the audio PA (TDA7502) the speaker internal or external is driven by pins 5 and 8 of the PA like the GP300 schematic says. You say L405 and L406 were removed - can you put them back and run the jumper then from other end of L405 (the side not connected to Pin 5 of U409) to the un-grounded side of C442? Doing that would keep the condition where no external speaker plug was connected from what I see. I'm kind of tired here looking at this so my read on this may be wrong.

Also is your internal speaker good? It may not be working....
Will
Posts: 6823
Joined: Tue Sep 04, 2001 4:00 pm

Re: GP300/P110 = Experts ???

Post by Will »

This is a very common problem. The jack switch does not make contact when the speaker mic is unpluged.
The cure is to replace the jack assembly or add a jumper from the audio IC to the flex so the internal speaker works.
Satelite
Posts: 672
Joined: Sat Aug 12, 2006 10:43 am

Re: GP300/P110 = Experts ???

Post by Satelite »

Hello :
Yes internal speaker is working.
Leave it up to me to do it the hard way ! :lol:
Will run the jumper as mentioned and replace L405 and L406.
I didnt want to replace the jack as it looked like id have to unsolder a bunch of components from the back side to get at the jack solder points and then resolder everything back.
Since i wasnt interested in using a speaker mike anymore i was going to bypass it.
Is it necesary to actualy unsolder the components from the back side of the adaptor jack to put in the new jack ?
Thank you
Satelite
Will
Posts: 6823
Joined: Tue Sep 04, 2001 4:00 pm

Re: GP300/P110 = Experts ???

Post by Will »

Satelite wrote: Is it necesary to actualy unsolder the components from the back side of the adaptor jack to put in the new jack ?
Thank you
Satelite
Yes, the RF jack, antenna contact, and switches have to be removed to get at the jack assy. Not fun, but I have done hundreds. I have seen my share of butchered boards too.
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