Help with wiring issue on Epi SG Special P90

Discussion in 'Tone Zone' started by iloveparis, Jul 10, 2020.

  1. iloveparis

    iloveparis New Member

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    I have a brand new 2020 Epi SG Special P-90 purchased from Zounds about a month and a half ago. Been playing it everyday and loving it.

    Recently I noticed something odd with the controls: When selector is on bridge pickup, turning down the neck pickup tone control (which should have no effect) darkens the sound. And even with both tones wide open, the bridge PU doesn't sound as cutting as it should.

    I took off the back cavity plate - there's no obvious hanging or unsoldered wires. The PUs have quick-connectors so I tried a test: in the bridge PU position, I disconnected the neck PU. Sure enough the tone changed the the more aggressive bridge sound I remembered, and the neck tone pot stopped having any effect.

    Verdict: in the bridge selector position, both pickups are active (this is not correct behavior, right?) Is this a problem in the switch? In the wiring? Could. I fix it myself?

    I know just a little bit about soldering (I installed a new switchcraft jack in my Mustang), but little to nothing about circuits.

    Some photos of the harness:

    IMG_0771.jpeg IMG_0770.jpeg IMG_0769.jpeg IMG_0767.jpeg
     
    Last edited: Jul 10, 2020
  2. iloveparis

    iloveparis New Member

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  3. Biddlin

    Biddlin Well-Known Member

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    Is it still under warranty? Get it fixed at an authorized repair shop.
     
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  4. DrBGood

    DrBGood Well-Known Member

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    Before bringing it in, check if the ground doesn't touch this blade or the other.

    .jpg
     
  5. iloveparis

    iloveparis New Member

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    Thanks, I’ll try that

     
  6. iloveparis

    iloveparis New Member

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    Ground Doesn’t appear to be touching those blades but I’m not sure exactly what to look for. Does this view help?

    Also of note: even with neck PU disconnected, both bridge and neck tone controls are affecting bridge PU

    thanks for the help!
     

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  7. DrBGood

    DrBGood Well-Known Member

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    OK, no problem on that end.

    When you say neck control affect bridge pup, is the toggle switch in the middle position ?
     
  8. Von Trapp

    Von Trapp Well-Known Member

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    I'm no expert when it comes to looking at wiring like this but as far as I know that outer wire from the pickups is supposed to go to ground but in the pic it looks as if they go into those plastic things. I'd look into if they go to ground somewhere and also where they go in the plastic things.
     
  9. donepearce

    donepearce Well-Known Member

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    On your last picture in the group it looks like the hot terminal of the tone control is possibly touching the hot of the output jack. Can you check that?
     
  10. iloveparis

    iloveparis New Member

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    I dropped it at a LGS that's an authorized Epi repair center. If it was an old beater I'd DIY this but since it's under warranty I want it factory-repaired. I will update!
     
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  11. DrBGood

    DrBGood Well-Known Member

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    Good eye ! That tone pot shoud be rotated 90 degrees to clear the jack.
     
  12. iloveparis

    iloveparis New Member

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    Ugh, looking at it now it seems so obvious. Also the tone pots got adjusted recently as I was installing pointers. Grrr I bet that's it, but I didn't take enough time to really look. Now I need to wait 10 days while the shop has it!

    Thanks for the scrutiny y'all.
     
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