Fender MIM Jazz (fretless) passive pickups stopped working. Cause? Fix?

Discussion in 'Pickups & Electronics [BG]' started by longfinger, Jul 3, 2019.


  1. Hello Talkbass hive mind.

    I have a Fender Jazz MIM fretless bass, with passive OEM pickups that was my favourite bass right after I bought it. Years passed, Things changed, I started playing upright, and other bass guitars, then it seems that many more years passed before I played this bass again. When I did, I was shocked at how low the sound was, and how one pickup was dead. I used my new favourite bass guitar for the gig and told myself that I was going to fix the fretless. I work on cruise ships and go months without playing the instruments left at home. Another year later, and I'm now wanting to fix this bass.

    I just tested it and it is completely dead now. No sound. Testing Amp and cable work fine. I figure it could be corrosion. Years of no-use. I take the pick guard off, see no unattached wires, no broken solder. Output jack looks ok. I use contact cleaner and remove gunk from the pickup contacts, spray inside the pots, jiggle cables, clean things. Still nothing.

    Perhaps a cable is broken inside its insulation? Any ideas of what might be wrong? Do passive pickups on basses like this just die?

    jazz pups.jpg
     
  2. bpc

    bpc

    Mar 29, 2016
    Central Scotland
    You can test the pickups with a multi-meter. You should see anything from around 6k to 15k resistance between the wires coming from the pickup. You'll need to disconnect the pickups from the pots first. If you get infinite resistance through the pickup then the wire of the coil is broken somewhere inside the pickup and it is toast. Someone may know what resistance you should expect from these particular pups.
     
    longfinger likes this.
  3. Arie X

    Arie X

    Oct 19, 2015
    you're gonna have to trouble shoot step by step with a multimeter or take it to a shop.

    as stated above, a basic continuity test can be done by detaching each pick-up from it's pots and using your multimeter. set your resistance level to 20~25K and probe. typical resistance level should be around 7K or so. if the meter flatlines, look at the input/output lead solder points and verify that they are whole. it isn't often that coils short out internally unless there is a break in the wires insulation from abrasion or other damage causing a short -but it's real hard to find. at that level it's less trouble to just replace the pick-up.

    if the pickups pass muster, then take the investigation to the pots and move your through to the jack. if nothing has been diccovered then take it to a shop.

    fwiw, be real careful taking the covers on and off. the input and output leads down there attached to the pick-up base plate are super fragile and break easily as they are around .003 in diameter.
     
    Last edited: Jul 4, 2019
    longfinger likes this.
  4. Turnaround

    Turnaround Commercial User

    May 6, 2004
    Toronto Canada
    Independent Instrument Technician
    A short can also cause no output. Plug a lead cord into the jack. At the other end of the cord, use a multimeter to read the resistance between the tip and the ring of the plug. If it’s zero( or close) there’s a short somewhere. Check for strads of wire touching where they shouldn’t or something touching a control contact that shouldn’t.
     
    Gravedigger Dav and longfinger like this.
  5. Check the output jack for corrosion. It happens to any bass not used for awhile. just open up the control cavity and use some emery paper on the output jack where the barrel and the tip contact the jack. It is often the problem.
     
    longfinger likes this.
  6. Thanks for the suggestions!
     
  7. I finally just took to bass in to a local guy, after I putzed around with a multi-meter.

    He unsoldered each component to test it, and finally found out the pickups themselves are dead. Tested like they were not there. Some cable inside it broke, shorted, who knows.

    So now I just need to replace the pickups (stock MIM Fender Jazz from late 2006) with something.

    So many choices.

    Basically I want reliable, strong output and and low (no?) noise when one pickup is favoured over the other. The rest I'll deal with at the amp.

    I'm curious, what are the opinions on how the $8 eBay generic pickups stack up against the $100 brand name pickups? It's all 70 year old tech right?
     
  8. Primary

    Primary TB Assistant

    Here are some related products that TB members are talking about. Clicking on a product will take you to TB’s partner, Primary, where you can find links to TB discussions about these products.

     
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