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Low output from neck PU....HELP

Discussion in 'Pickups & Electronics [BG]' started by Psycho Funk, Apr 8, 2005.


  1. I'm an electronic idiot and I would like some help from the experts. I have a Geddy Lee Jazz that I've reinstalled the original PUs and the Neck PU has very low output. I've checked the solder/contact and the grounding. this PU had been out a few months and worked well previously. The bridge PU is fine.

    Thanks for your help.
     
  2. danomite64

    danomite64

    Nov 16, 2004
    Tampa, Florida
    Where did you check the soldering, at the controls? Sometimes the wire comes loose at the pickup, too. Also, sometimes the pickup just needs to be raised to get louder.
     
  3. The soldering connections at both ends seem well connected. How do I determine if the problem lies with the PU of the Pot?
     
  4. luknfur

    luknfur

    Jan 14, 2004
    DIXIE
    FWIW:

    a pup usually either works or it doesn't in terms of output. I doubt it's the pot either but you can put an meter on the pot and see if you get a full sweep. The further a pup is from the strings the more the output will drop. Probably 1/4" for it to be marked. Does it sound like the pups are out of phase when you mess with the volume controls? Possible poor ground maybe. If the cavitie's shielded, you maybe getting a partial short - although it's usually all or none.

    It's probably either wiring or adjustment - something related to the install.
     
  5. Thanks for the help. I took it to a pro and found the PU wire to be in need of a rewind, not repairable. I must have severed the wire somehow.
     
  6. luknfur

    luknfur

    Jan 14, 2004
    DIXIE
    FWIW:

    Sounds kind of wierd. If the pup was working at all, there was some connection going on cause there is only a start and finish to the winding in that pup and you have to have a complete circuit to get sound. I had a cheap Ibanez J quit working on me once and the end of the winding had detached from the solder point. Tacked it back and it worked fine. If there was some connection, then there should be enough to tack it back. It's a bit delicate but I'm practically blind, far from steady handed, and pulled it off. Somebody with good eyesight and a steady hand could probably tack a winding too short to reach the solder point. The external leads are no problem to reattach.

    Like a physician, I'd get a second opinion. You got nothing to lose and everything to gain.
     
  7. Well as you can tell, I'm truly an electronic idiot but I'll try to describe what I saw when we tested the PU. First off, we tested both PUs with an ohm meter and found the neck PU to be much weaker than the bridge pu. On inspection, the winding had two areas of fraying and 4 distinct free ends. We tried to unwind and reattach them to no avail.

    Does any of this make sense? I'm trying to use this as a learning experience and I appreciate your input.
     
  8. luknfur

    luknfur

    Jan 14, 2004
    DIXIE
    FWIW:

    Hmm. Not something I've experienced. But obviously the pup is damaged. The winding is one continuous coated strand of wire but in terms of a circuit, since any broken lead is in the magnetic field, it's more like two open ended conductors fed into a bucket of electricity than a single wire with electricity being pumped through it.

    At any rate. Because I frequently handle and swap pups in and out, something I do is throw a piece of scotch tape over the base of the housing to hold the covers firmly in place. For me those loose covers were a royal pain. They're great for re-windng a pup or having the option for an internal repair but useless to my knowledge otherwise.

    You could definetly replace the pups used (and probably new) for what a re-wind would cost. Probably a good basis if someone wants a custom wound though. You'd have no problem selling one good one and one damaged (basically tossing the damaged one in). Or keep them for a project and pick up something else you've been wanting to try - could be damaging the pup's the best thing that could have happened (or a nightmare in progress)