Help troubleshooting Seymour Duncan STC-2C-BO Preamp battery drain in a Squier Bass VI

Discussion in 'Pickups & Electronics [BG]' started by Flad, Jan 25, 2018.


  1. Flad

    Flad

    Apr 18, 2014
    The title pretty much says it all. I installed a SD STC-2C-BO 2 band EQ in my Squier VI. For the first year batteries would last 3-4 months with daily play. Now no matter how much I use it or don't the battery only last about 2-3 weeks.

    I've looked inside the control cavities and nothing jumps out at me, how do I trouble shoot this. It's got to be a short somewhere right?
     
  2. sissy kathy

    sissy kathy Back to Bass-ics Gold Supporting Member

    Apr 21, 2014
    Arbutus, MD
    Have you gotten lazy and quit unplugging it after play?
     
    Killed_by_Death likes this.
  3. Flad

    Flad

    Apr 18, 2014

    I should have said so in my original posting. I don't play it on a daily basis like I used to. I put a new battery in before my last gig, the Friday before New Years, it's been in the case ever since until yesterday. I literally got to play for about 45 minutes on this last battery, I only use it for one set if at all. The first time I noticed it was happening was sometime around Halloween. I'm on my 5th battery in four months. I never leave my guitars plugged in, I even unplug between sets at shows.
     
  4. sissy kathy

    sissy kathy Back to Bass-ics Gold Supporting Member

    Apr 21, 2014
    Arbutus, MD
    They don't appear to have a stellar performance record; amazon is reporting a 20% failure rate. (1 failure in 5 reviews, not a large sample.) Before you give up completely make sure the circuit board isn't contacting the shielding (if any.)
     
    Flad likes this.
  5. Make sure the negative of the battery is not shorted to ground in some manner. Use a continuity setting on your multimeter or use the ohms setting
     
    Flad likes this.
  6. Zoobiedood

    Zoobiedood Commercial User

    Sep 1, 2015
    Writer/Ambassador/Artist/Resident Bass Expert for Seymour Duncan
    My first thought is that somewhere the battery is shorting to ground. If you go over the electronics and can't pin it down to anything, send me a PM, and I will let you know the right person to contact about this at Seymour Duncan.
     
    Flad likes this.
  7. Flad

    Flad

    Apr 18, 2014
    Thanks for the replies everyone. I just pulled the old battery to put a new one in and did a continuity check between the negative battery terminal and a screw on the control plate and got a nice loud BEEEEP, checked on the bridge too just for fun, same result. There must be a short somewhere. Any suggestions on the best way to find it? I can't do more today because I'm going to play it tonight at a party but I plan on digging in tomorrow afternoon.

    When I was researching I saw in a different thread about how this kind of thing is almost always the jack. I would assume to test this I need to disconnect it and check for continuity between the battery lug and ground lug? Is this correct?
     
  8. Killed_by_Death

    Killed_by_Death Snaggletooth Inactive

    Yes, when you put in a 1/4" instrument plug it makes contact between the ring & sleeve.
    So, with the jack *disconnected, check for continuity between the ring & sleeve.

    *you only need to remove the lead from the ring terminal in order to check

    add: if the preamp is working you can do what Sissy Kathy recommends in the next post
     
    Last edited: Jan 27, 2018
    Flad likes this.
  9. sissy kathy

    sissy kathy Back to Bass-ics Gold Supporting Member

    Apr 21, 2014
    Arbutus, MD
    I don't think you need to disconnect anything. Setting it to volts, if there is a short there it will read 0; if no short it will read 9 volts.
     
    Flad likes this.
  10. Killed_by_Death

    Killed_by_Death Snaggletooth Inactive

    Yes, but the short could be anywhere. If you don't disconnect it you won't have isolated the problem.
    We already know there's a short, now the trick is to find where.

    Isolating components is a good start.

    (but be more clever than me & check for the voltage drop instead of disconnecting it) :wideyed:
     
    Last edited: Jan 27, 2018
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  11. sissy kathy

    sissy kathy Back to Bass-ics Gold Supporting Member

    Apr 21, 2014
    Arbutus, MD
    NO, you are checking the jack, the pre still works, so if the jack is operational you will still read 9 volts. With the pre working you have to be getting 9 volts there, unless the jack is shorted.
     
    Killed_by_Death likes this.
  12. Killed_by_Death

    Killed_by_Death Snaggletooth Inactive

    DOH!, you're right. There will be a voltage drop if it's not shorted.

    (if the pre is working)

    I'll bet the jack is shorting :thumbsup:
     
    Last edited: Jan 27, 2018
  13. Flad

    Flad

    Apr 18, 2014

    Yes sir, I get a 0 reading so it's gotta be the jack. Thanks folks!
     
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  14. Flad

    Flad

    Apr 18, 2014
    I just got to wondering, is there a way to repair this jack or is she a goner? It's Sunday so it's not like I can just run to the store and grab one.
     
  15. sissy kathy

    sissy kathy Back to Bass-ics Gold Supporting Member

    Apr 21, 2014
    Arbutus, MD
    Whether or not it can be repaired is contingent upon how it shorted. Very often the contacts that touch the male jack are making contact and you can just bend the ring terminal contact out a little. For the short term that will hold, for a long term fix I would still replace it with a Switch Craft 1/4" stereo female jack.
     
    Last edited: Jan 28, 2018
    Zoobiedood likes this.
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    Primary TB Assistant

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