Finding the short

Discussion in 'Pickups & Electronics [BG]' started by knappymer, Sep 28, 2018.

  1. hello all. I’ll get right to it.

    I have an older, stock Ibanez BTB 576 and it will drain it’s 18volt power supply almost overnight. It has Bartolini mk2 pickups and the Ibanez bass, mid, treble with volume and tone; no mid shift switch.

    I have heard of the neutrik output jacks going bad on these things so I purchased a new one just in case it’s as easy as that. $5 shipped.

    First I would like to test for a voltage draw. Would I test the leads going to the output jack? In doing this would I inadvertently activate the circuit anyway and see a voltage drop no matter what?

    Basically, how would I find the short?

    Thank you all for your time in helping a fellow lowender out.
     
  2. Killed_by_Death

    Killed_by_Death Snaggletooth Inactive

    Take the batteries out & check for continuity between the ring & sleeve:

    Apr16_PG_CLM_Guitar-Shop-101_photo5_WEB.jpg

    Do this w/o a instrument cable plugged in. It should read infinity (no connection).
    With the instrument cable plugged in it should measure zero Ohms (Ω).

    If it reads zero Ohms in both situations, you've got a faulty jack.
     
    Reedt2000 likes this.
  3. Do the batteries go dead overnight without a 1/4 plug in the jack? Even left plugged in overnight, the batteries should still be fine unless there is some power hungry electronics in that bass.
     
    knappymer likes this.
  4. lz4005

    lz4005

    Oct 22, 2013
    If you've already got the new jack, just install it and see if another battery dies. Unless the bass was improperly rewired at some point, that's going to solve it 99% of the time.
     
    knappymer likes this.
  5. Thanks for the reply guys. I disconnected the old Jack before I tested it because that was a whole lot of corrosion that I found. I’ll install the new Jack today and see what happens.
     
  6. If you have a meter, while you are soldering in the new jack, connect the meter between the battery negative and the connector on the jack. Set the meter on the lowest amp setting, hopefully milliamps. It should read 0 with the plug out and some number possibly less then 1 but not more then 4 or 5 at the outside, with the plug in. The main thing is 0 with the plug out.
     
  7. Hey all.

    It appears the old Output Jack was the culprit. Going strong and back to kicking out the lowend.

    Thanks for the Help!