I have created this page to highlight problems with Amateur Radios which are not covered on the Internet and the faults are caused by component failures for which there are no new replacement components available.

  • This radio came in with poor Receive and Signal meter stuck
    at Sig 10, but tries to work while in transmit mode.
    All of the voltages into the multiplexer are correct, and the output waveform from the multiplexer to the CPU A/D are also correct.

    This unfortunately points to the failure of the radios CPU which is no longer available from Icom UK ether as a separate component or on a new main board.

    The only solution is to purchase a replacement board from a scrap radio to replace the blown one.

    I have seen other symptoms associated with the signal meter problems while looking for a replacement CPU which include being unable to switch the radio from receive to transmit.

    When you power the radio on, the normal start-up sequence is as follows: -

    1.      LCD displays all symbols.

    2.      Power setting say “H”

    3.      Normal radio display.

    When the CPU has failed the LCD display all symbols (1)
    fails to appear as if the initialising program fails to complete.