JTM 45 BB RI R19 resistor disconnected

Discussion in 'The Workbench' started by randrewrussell, Oct 26, 2021.

  1. randrewrussell

    randrewrussell Member

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    Ok I am starting to fix the amp and noticed when I opened her up that the R19 resistor appears to be half broken or disconnected from the PCB. Does anyone know what R19 is there for?
    Thanks
    RAR
     
  2. neikeel

    neikeel Well-Known Member

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    If it is according to my schematic the cathode follower 100k and the amp probably sounds very bad and your tone pots will not work.
     
    Dblgun and Pete Farrington like this.
  3. Pete Farrington

    Pete Farrington Well-Known Member

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  4. randrewrussell

    randrewrussell Member

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    Pete Yes! I thought a 100k resistor? cathode follower? My amp appears to be an early 89 RI.
    Well I have to figure out how to upload a photo. Thanks
     
  5. Pete Farrington

    Pete Farrington Well-Known Member

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  6. neikeel

    neikeel Well-Known Member

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    ???:facepalm:
     
  7. randrewrussell

    randrewrussell Member

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    Very interesting read. It's a learning curve. Any thoughts on doing work on PCB boards from the top side rather than the bottom? I want to make just a few mods.
     
  8. neikeel

    neikeel Well-Known Member

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    Generally don’t. It’s bad practice, lazy and likely to let you down.
    See what the others say.
     
  9. randrewrussell

    randrewrussell Member

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    ok isaw a vid where the guy did it
     
  10. Gene Ballzz

    Gene Ballzz Well-Known Member

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    ^^^^^^^ What He Said! ^^^^^^^

    With the caveat that clipping an original component and leaving the legs protruding to experiment with various/multiple new values for a specific, desired modified outcome is not so bad. Once you determine the final desired components though, you should pull that board and finish the job correctly! We can all certainly relate to not wanting to R&R a printed circuit board "umpteen" times!
    Just My :2c:,
    Gene
     

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