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Uniden washington PC-385 PCB It has no receive, and no modlation, I replaced the IC4 audio chip, it has modulation now but still no receive, I tried aligning L10- L5 and still noting. it rec when I key up another radio right next to it.

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  • rschaniel961 Mar 21, 2011

    Well I replaced the ta7222ap and the and the MB3756 regulator, and still no receive on either ssb or AM the meter isn't even moving



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Hi you may need to to change the audio transistor also ,also check with external speaker

Posted on Mar 16, 2011

  • this is a scam website Mar 22, 2011

    hi sounds to me there are other problems along the board check for voltage at ta7222 before and after check ic aswell this could be the source of the problem check all components on the track leaving mb3756 you will source the fault along the track it would be easier if you have an ocilliscope to check the source hope you get to the bottom of it goodluck



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Hi and welcome to FixYa,

Initially, pls confirm that there is modulation (transmit audio). The reason I asked is if IC4 (TA7222P) is blown, then the radio would have no audio amplifier which would explain no receive audio. Additionally, the final and pre-final (TR15 & 15) gets is modulated TX+12 through D8 from T1 which in turn is the output of IC4 through C48.

Perhaps a schematic diagram may be of further help.

Good luck and Thank you for using FixYa. Happy Holidays.

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1 Answer

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Most modulation problem could be traced to:
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Hope this be of initial help/idea. Without a model number, I can't be more specific as to component(s) or PCB location but pls post back for any developments (or lack thereof) or should you need additional information.

Good luck and kindest regards.

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