Troubleshooting ground problem

Discussion in 'Tele-Technical' started by Zeellee, May 26, 2020.

  1. Zeellee

    Zeellee TDPRI Member

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    Hi! Can anyone help me understand if this wiring is correct? It's a 4-way switch tele with a reverse controlplate. The positions should be from left to right: series -> neck-> parallel -> bridge.
    Everything seems to work fine but when in position 1 (bridge) and 4 (both in series) i get this nasty buzzing noise that makes it unplayable. I'm sorry if the drawing is a mess, did the best i could with paint.
     

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  2. Peegoo

    Peegoo Friend of Leo's

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    Do you have a string ground? I ask because the circuit diagram looks correct, and symptoms you describe are common when there's no string ground.

    It's a wire that runs from common circuit ground to the bridge plate. You can test this by using a multimeter set to read continuity (or Ohms). Test across the control plate and the bridge plate. You should have continuity.

    What is the G represent in your diagram? If it means 'ground', the neck pickup is incorrectly wired.

    Look here (click on the pic):

    [​IMG]
     
  3. Ronkirn

    Ronkirn Doctor of Teleocity Vendor Member

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    it appears you have the black from your neck pickup connected to ground.. wrong..

    only the connection going to the neck pickup cover is grounded... in the Seymour Duncan diagram Peegoo posted you will note the lead jutting from the volume pot heading to the right labeled "ground wire from bridge"... that's wrong. it always has been. it should be labeled "Ground wire from neck pickup's cover".

    The bridge is grounded through the bridge pickup's mounting screws mounted through the bridge into the baseplate on the pickup,, however you can, if necessary, run a secondary ground lead. in that case it would be connected to the pot case too.. in some pickups that have no baseplate, the screws may be isolated from making a ground connection..

    To get that ground wire you clip the little jumper going from the black lead to the cover then solder a third wire, usually yellow to the cover ONLY... it is connected to a ground point in the electronics cavity, usually the pot case..
     
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  4. Zeellee

    Zeellee TDPRI Member

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    Thanks for the reply. I think what you're referring to would be the grey thing on the bottom right that sits under the bridge. I checked and i do have continuity from the pots to it
     
  5. Peegoo

    Peegoo Friend of Leo's

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    The note box in the Duncan diagram ("important") specifies the separate ground wire from the neck pickup. The "ground wire from bridge" is correct because not all Tele bridge pickups have a metal base plate.
     
  6. Zeellee

    Zeellee TDPRI Member

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    Yes those are ground points...see below

    I actually did clip the jumper on the neck pup cover but forgot to add it in the drawing...my bad. The third wire...could it be the one going from the volume pot to the dot on the cover? I noticed that it's kinda wiggly but i tought that since the problem only occurs when the bridge pup is involved that was the problem
     
  7. Ronkirn

    Ronkirn Doctor of Teleocity Vendor Member

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    connecting that 3d wire to the neck cover can be a but problematical for some.. since most are chrome plated.. that chrome must be removed... use sandpaper,. or a Dremel to remove it all the way down to the brass or nickel silver ... then solder to that.

    try this schematic. electrical it;s the same as the Seymour Duncan one, it's just easier to understand..

    [​IMG]

    r
     
  8. Zeellee

    Zeellee TDPRI Member

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    So you think that the neck pup is the culprit? I noticed that there was maybe wax keeping it down...I should just solder it back on the cover so it doesnt move around anymore right?

    That's the situation right now
    86b576e2-f9ba-4cc5-b9e3-bdb009a70f8b.jpg
     
  9. Ronkirn

    Ronkirn Doctor of Teleocity Vendor Member

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    well . . . soldered there the wire could rub against the inward edge of the rout too... and that solder connection is almost certainly being held in place by the rosin flux acting as a glue.. you could probably pick it off with a fingernail... none of us can solder directly to a chrome plating... it has to be removed...

    here's the jumper that must be cut and how to connect the wire to the cover.. use the mounting tab, with the chrome removed..

    sorry about the focus.. the autofocus needs glasses... :p

    r

    DSC_8441.jpeg DSC_8442.jpeg
     
  10. Peegoo

    Peegoo Friend of Leo's

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    It looks like your pickup has no mounting tab there in the center.

    [​IMG]
     
  11. Zeellee

    Zeellee TDPRI Member

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    Ok...i kinda lost you guys here. You're telling me that the wire going into the cover should NOT be moving at all right? So i need to get it off, clean and sand down a bit and resolder it (how do i remove the wire, i just pull it or do i risk of breaking something?). Then, i need to solder something (what exactly?) to the mounting tabs. Also, my pup looks like that i don't see any tabs
    175c9552-8b66-430a-8758-9ee5d6e7089d.jpg
     
  12. Ronkirn

    Ronkirn Doctor of Teleocity Vendor Member

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    see the wire running from the contact to the hole in the bobbin. That wire goes to the pickup cover... clip it or unsolder it from the contact point and solder the third wire to it..

    there should be ZERO continuity between the third wire and either of the two solder contact points.. if there is, it means the coil is shorting out to the cover internally and cannot be used for the 4 way circuit. the pickup can still work it it is shorting out.. just not in a 4 way configuration..

    r
     
  13. Ronkirn

    Ronkirn Doctor of Teleocity Vendor Member

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    OK. it looks like it's done correctly in post #8. but is the black ground wire connected to a riveted contact? Is it loose?? is there any continuity between either of the primary coil contacts and the cover?

    r
     
  14. Zeellee

    Zeellee TDPRI Member

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    Yeah there's continuity with one contact (the one with the black wire going to ground) but the soldering going into the cover it's loose so it comes and goes
     
  15. Zeellee

    Zeellee TDPRI Member

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    Also there are 2 black ground wires, one coming from the ground on the volume pot and going straight into the cover and one coming from a ground point screwed to the body. This last one goes to one of the two contact points of the pickup. From this same solder point there was also a tiny wire going back to the riveted contact on the cover, but it has been snipped off as you can see in post #8. Thank you for following this mess ahah
     
  16. Ronkirn

    Ronkirn Doctor of Teleocity Vendor Member

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    that's not good for the 4 way... there also should be some reading to the other contact to the cover.. but if there is continuity.. you're outta luck on this one...

    r
     
  17. Zeellee

    Zeellee TDPRI Member

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    I guess i'll figure something out, thanks anyway. One last thing about that loose contact on the cover...what's the correct way of soldering it back on? I can't seem to find anything about it online
     
  18. Ronkirn

    Ronkirn Doctor of Teleocity Vendor Member

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    you must remove the chrome plating using sand paper or a Dremel tool.. then just solder it... solder will NOT stick to chrome...
     
  19. Zeellee

    Zeellee TDPRI Member

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    Yeah but how do i get it off the cover first? I just pull it?
     
  20. Ronkirn

    Ronkirn Doctor of Teleocity Vendor Member

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    do not worry about it... remove the chrome in the narrow area beneath the contact .. that's all the area to solder the lead to that is required..

    r
     
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