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RCI issues

Discussion in 'CB and Export Equipment and Accessories' started by 743SEPA, Nov 10, 2018.

  1. 743SEPA

    743SEPA New Member

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    I have a 1st gen RCI 2950 that all of the sudden won' t rx or tx. Sometimes just keying the mic fixes for a little while. Doesn't matter if it's hot or cold. Sometimes turning it off then back on it will come alive,other times not. I just replaced the battery and added a max mod but had these issues before. Worth sending out for repair?


     

  2. 9C1Driver

    9C1Driver Sr. Member

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    If you have tried a different mic and that didn't help could be a cold solder joint. You can also check the soldering points at the edge of the board where it wraps around. With the cover off next time it acts up take the eraser side of a pencil and push on different sections of the board. There are plenty of sharp members here that I am sure will respond in the next day or so.
     
  3. Robb

    Robb Yup

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    Yeah . . . I have one of those too and it does the same thing.
    Factory flaw with the logic board and is not fixable IIRC.
     
    Shadetree Mechanic likes this.
  4. nomadradio

    nomadradio Analog Retentive

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    Have a look at solder connections along the side and rear edges of the circuit board. There are parts bolted to the side and rear rails, using the aluminum as a heat sink. The legs from these parts are lapped over the edge of the circuit board and soldered. If you gently pull the side rail outwards a bit, watch for movement from any of the component legs that reveals a cracked solder connection.

    Might be that simple, might not.

    73
     
  5. jon666

    jon666 Sr. Member

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    cold solder joint is my guess. without pictures
     
  6. Shockwave

    Shockwave Sr. Member

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    I have to agree with Robb on this one. I've had two with this problem. The older one came back changing the lithium battery. The newer one as I recall may not even have a battery but the issue does seem related to the microprocessor on the front panel board. Not cold solder joints unfortunately.
     
  7. 743SEPA

    743SEPA New Member

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    I thought I had it fixed by replacing the battery,worked great for a while then started acting up again. I did go over some solder joints that looked questionable but may have to look a little harder/deeper. Who is a good tech on these rigs?
     
  8. jon666

    jon666 Sr. Member

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    i have a brand new 2995dxcf never had the cover off.like i said before
    if its not broke dont fix it or tinker. now days everyone wants to mod the hell out of a new radio. if it breaks ill repair it.
     
    SIX-SHOOTER and undertaker like this.
  9. kaos513

    kaos513 Well-Known Member

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    I remember the 2950 having chip issues
     
  10. 743SEPA

    743SEPA New Member

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    I went all over the board and did find a broken joint along one edge and fixed that,touched up a couple more. Turned it back on,no tx or rx. Tx indicator on display comes on but no output. I cycled power and it came alive. With the cover off I went all over the board with a pencil eraser and it never cut out. Is this worth pursuing?
     
  11. Robb

    Robb Yup

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    Like any radio repair, it is going to take a bit of persistence.
    Yes, it is worth it if it doesn't have a cpu issue.

    How old is the radio? May well have other problems with the electrolytic caps. More often common - than not.
     
  12. nomadradio

    nomadradio Analog Retentive

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    The "TX" indicator on the LCD display only shows that you keyed the mike.

    In this radio, the mike's keying wire leads into the radio's display computer. The computer has a separate output wire that leads to the analog keying circuit on the radio's big pc board. If the computer is working, it activates that output wire when you key the mike.

    If the radio's PLL has dropped out of lock, or if a bad solder joint shuts down the transmit, the computer won't know about it.

    The indicator on the display only says the computer tried to key the radio. The computer won't know whether or not it worked.

    Really makes it sound like the trouble is downstream from the computer.

    73
     
  13. Shockwave

    Shockwave Sr. Member

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    Keep in mind when the problem first starts, it comes back to life after a on / off power cycle that resets the CPU. If it were a VCO or PLL on the verge of unlocking, I would think the problem would first be noticed at one end of the band and not the other. That idea should be checked but the symptom does not appear to be solder joint related when a reset can correct the symptom until the next power off occurs. I believe if you swap front panels with the same generation radio, the problem moves with the panel.
     
  14. 743SEPA

    743SEPA New Member

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    Don't have the time or expertise to diagnose,time for it to find a new home.
     
  15. 711

    711 Active Member

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    This is a common problem in the VCO area. Specifically a cap. 5pF or something to that extent to ground. The fix was a 3pF , I'll have to go and search my notes
     

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