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  1. Radio Head Unit - Repair III

    .. continuation of Radio Head Unit - Repair II

    CD port not working
    Observed on: 1 EUDM Radio
    Fixed by: PCB repair, replacement of OP amp

    State: Fully understood

    Acid damage to the traces around the CD port OP amplifier can cause the connection to the CD changer to fail.

    Click image for larger version. 

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    severe trace damage around the CD port OP amp mounting point

    The CD port should be removed and cleaned. In addition to repairing ...

    Updated 21-01-2024 at 07:15 PM by Heineken

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  2. Radio Head Unit - Repair II

    .. continuation of Radio - Repair

    Too little Volume and Distortions increasing with Volume

    Observed on: 1 EUDM Radio
    Fixed by: OP amp replacement
    State: Fully understood

    The audio signal path on these radios is fully analogue with several operational amplifiers at various stages. One of them is IC303, a 20 V, 10 MHz quad operational amplifier from JRC/NJM: NJM2060M.

    Click image for larger version. 

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    IC303 at the rear end of the lower PCB
    ...

    Updated 12-07-2023 at 09:28 PM by Heineken

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