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Ampeg SVP Pro power issues

Discussion in 'Amps [BG]' started by THE DANiMAL, Oct 20, 2013.


  1. THE DANiMAL

    THE DANiMAL

    Nov 22, 2007
    Bartlett, IL
    So I just picked up an SVP Pro from t buddy, sounds killer except it randomly shuts of for like 30 seconds after just a few minutes of playing. Any thoughts on what could be causing this?
     
  2. cableguy

    cableguy Supporting Member

    Jun 4, 2009
    North Bend, WA
    Does the power shut off (lights) or just the sound?
     
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  4. THE DANiMAL

    THE DANiMAL

    Nov 22, 2007
    Bartlett, IL
    Oddly enough, no sound, no lights, but it's still on, tubes stay lit and there's still power running.
     
  5. THE DANiMAL

    THE DANiMAL

    Nov 22, 2007
    Bartlett, IL
    So when it shuts off, if I tap it, it turns back on. No joke, I can tap it anywhere and it'll
    Turn on. It also crackles when I tap it.
     
  6. Dave W

    Dave W Supporting Member

    Mar 1, 2007
    White Plains
    Pull the top off and check the ribbon cable that connects the two boards inside of it. Make sure it's well connected on both ends.

    It's a really crap design and falls out quite easily with nothing to really hold it in place.
     
  7. THE DANiMAL

    THE DANiMAL

    Nov 22, 2007
    Bartlett, IL
    Yeah, the ribbon is fine, I just took the back end out to check for bad solder joints, it's all good. My guess is something on the front end maybe? My initial thought was tubes, but they're all good. I did a fresh swap earlier today to try to fix the issue. I almost feel like it's a ground issue, why else would the front end and sound go out and then kick back in when I tap it?
     
  8. Envincibal

    Envincibal Supporting Member

    Nov 22, 2008
    Philly, PA
    I had something similar with mine and it turned out the be a bad/cold solder joint - easy fix (make sure the power is off when you fix it and unplugged)
     
  9. THE DANiMAL

    THE DANiMAL

    Nov 22, 2007
    Bartlett, IL
    Hopefully I can tear it apart today and find out what's going on. The more I play around with it trying to diagnose, it's more apparent that its a solder issue. It cuts out after a certain amount of time which is really it shutting off at a certain temperature. So it makes sense.
     
  10. B-string

    B-string Gold Supporting Member

    A small wooden stick is useful to tap/wiggle lightly on components or gently flex pc boards when looking for intermittents. Hopefully is is not the HV winding on the power transformer.
     
  11. THE DANiMAL

    THE DANiMAL

    Nov 22, 2007
    Bartlett, IL
    I found some bad solder joints on the transformer, I resoldered all the connections from it to the board. That seems to have been the problem. I ran it for a little bit with no issues. I'll give it another run tomorrow to make sure everything is good. Thanks to everyone that gave input. You guys helped me figure it out quickly!
     
  12. B-string

    B-string Gold Supporting Member




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