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Thread: FT-991A Firmware Upgrade

  1. #1

    Default FT-991A Firmware Upgrade

    I downloaded the software for doing the 991A firmware update. It says to make sure the radio usb cord is plugged in and the radio is in
    C4FM firmware update mode. I switched it into C4FM mode. Not sure what "C4FM firmware update" mode is. Anyway it keeps telling me that
    the radio is not responding. Its COM3/COM4. I know this is correct because COM3/COM4 disappear from the ports list when I unplug the radio usb cable.
    Any suggestions?


  2. #2


    Download the Virtual COM port driver. It's on the same page as the firmware update. Extract the files, find them in File Explorer and run CP210xVCPInstaller_x64.exe or CP210xVCPInstaller_x86.exe. Do not connect the USB cable until prompted. Then try the firmware update.


  3. #3
    Super Moderator 5B4AJB's Avatar
    Join Date
    Mar 2008
    Meneou, Cyprus


    Failing that, try it on a machine with a real COM port - USB to COM port adapters are not all born equally :/

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