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ICom 7100 Reboots when transmitting at more than 50% power

Discussion in 'Ham Radio Discussions' started by N4QMI, Dec 14, 2020.

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  1. N4QMI

    N4QMI Ham Member QRZ Page

    My 7100 keeps shutting down and rebooting when approaching 50% power or more. I read another thread that he found his power supply to be defective. Here is a quick check I did:

    7100 turned on in receive mode: 13.7 volts
    7100 in tx mode at 50% 13.2 volt, then it reboots after a few seconds.
    I have checked all the connections going in and to the board. Sometimes it will start working again at full power. This problem just started about a week ago. I have checked the finals and all seems well. I am at a lose here.. Anybody know of anything that could this? I have checked a lot of other things as well but i need help.

    73 de N4QMI
  2. KD8DEY

    KD8DEY Ham Member QRZ Page

    RF Feedback on certain bands?
  3. N4QMI

    N4QMI Ham Member QRZ Page

    Oh i forgot to mention, it does this on a dummy load as well. All HF bands. 2 mtr and 440 no problem.
  4. G0JUR

    G0JUR Ham Member QRZ Page

    poor connections at fuse holders?? Usual fault.
    K8XG, ND6M, WZ7U and 1 other person like this.
  5. W9WQA

    W9WQA Ham Member QRZ Page

    yeah, gotta check volts right at radio connector
  6. WA4SIX

    WA4SIX Ham Member QRZ Page

    Ditto on the fuse holders...

    WZ7U likes this.
  7. WZ7U

    WZ7U Ham Member QRZ Page

    It's not an Icom bug, it's a feature!
  8. KD8DEY

    KD8DEY Ham Member QRZ Page

    Darn Energystar
  9. NK7Z

    NK7Z Ham Member QRZ Page

    Does the Power Supply voltage droop on transmit? Look at your 12 volt line to make sure... If it were me, I would connect a meter to the 12 V line, then transmit. If I saw droop, then I would suspect the Power Supply.
    WA9SVD likes this.
  10. N9SD

    N9SD Ham Member QRZ Page

    Hearing this makes me wonder if you've had more than usual humidity in the air and maybe some connectors have some oxidation build up on them. Maybe spray some contact cleaner on all electrical connections.

    Did you change anything else about a week ago? Different antenna? Different ground? New mode? New mic or speaker or anything that plugs into the radio?

    Also, how long is your power cord from the power supply to the radio? And is it coiled up anywhere? I had a similar experience with a 706mkII in my car - the guy who ran the power for me coiled up about 20' of power supply cable under the dash. Whenever I'd hit high power, the voltage would draw down and the radio would spaz out. Once I found the 20' coil and removed it, all better!

    Inside the house I run an IC7100 with a Samlex SEC-1235M power supply. I've experienced no such problems.

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