Potential grounding issue - do you see anything wrong here?

Discussion in 'Tele-Technical' started by NateD81, Aug 4, 2019.

  1. NateD81

    NateD81 Tele-Meister

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    88967790-3E8A-4A76-9410-C99C5908370A.jpeg 113B1416-36D3-4AB2-B978-A7D3E57694B4.jpeg 956551A2-8631-4078-B8D6-F4203DD67DEE.jpeg

    I’ve got a grounding issue that’s driving me crazy. I have checked everything I can think of for continuity and I can’t seem to find anything wrong. I’ve got continuity everywhere, yet, when I plug my guitar into my amp, I’m getting that classic buzz that goes away when I touch anything metal on the guitar.

    I have 68 Custom Vibrolux Reverb and really only notice the buzz when the bright switch is engaged, however it’s always there regardless.

    I tried known good cables, another guitar, different locations in my house, I’ve definitely isolated the issue to the guitar but I’m at a loss with where my issue is.

    Does anything look off in these photos?

    I’m at the point where I’m considering re-doing the wiring with gavitt wire and do copper shielding - just wanted to get some feedback from people who know way more than me before I go to town.
     
  2. kbold

    kbold Tele-Afflicted Silver Supporter

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    Check that the bridge plate is properly grounded.
     
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  3. jimilee

    jimilee Tele-Afflicted Silver Supporter

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    ^^^ in addition to the bridge wire, I can’t tell, are the two pots connected to each other? I see you have stuff grounded to the backs of each.


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  4. Andy B

    Andy B Friend of Leo's Silver Supporter

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    Using a DVM check for continuity between the bridge plate to the control plate and the back of the pots. Also make sure the output jack is wired properly.
     
  5. NateD81

    NateD81 Tele-Meister

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    That was one of my first concerns as I’ve had that be the issue in the past. It at least appears to be ok as I’ve got continuity when I check the bridge plate to the jack and also to the control plate and pots — would that indicate the bridge plate is grounded or could I still have an issue?

    I’ve got a 50s classic series tele and it doesn’t have a wire running from the bridge plate to the ground on the tone control, but it seems like the pickup has a ground on a screw that’s making contact with the bridge plate...not sure if that makes sense how I’ve described it.
     
  6. jimilee

    jimilee Tele-Afflicted Silver Supporter

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    What are we looking at, did you install a 4 way switch?


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  7. NateD81

    NateD81 Tele-Meister

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    The two pots are connected together on the outside lug, which then connects to the 3-way switch.
     

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  8. NateD81

    NateD81 Tele-Meister

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    Just a standard 3 way switch - single coils
     
  9. strat a various

    strat a various Friend of Leo's

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    I made a tool with just insulated copper wire and two alligator clips. Usually, If I keep trying connections until the buzzing stops, I can find the problem. Usually.
     
  10. NateD81

    NateD81 Tele-Meister

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    Good idea - I think I’ll give that a shot.
     
  11. strat a various

    strat a various Friend of Leo's

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    Only use this on a guitar ... if you use it on an amp, you could die ... like a ribbon mic hooked up to phantom power at a Peavey auction. And Gibson wouldn't even care. (Snif, sob)
     
  12. NateD81

    NateD81 Tele-Meister

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    Totally - Aside from changing tubes, I leave that kind of stuff for people who know what they’re doing. Good advice though!
     
  13. TeleTucson

    TeleTucson Tele-Afflicted

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    You're sure you've got your polarity correct on the jack (i.e., sleeve is ground)? Also, from the photo (as @jimilee points out) it looks like you've got the lug on the volume soldered to the case and the cap to the tone pot, but the only ground connection is through the case contact with the control plate on the nut side of the pot. I'd rather have that case wired to ground with solder than rely on contact ground. Additionally, that lug soldering to the case looks a little flakey anyway.
     
    Last edited: Aug 4, 2019
  14. NateD81

    NateD81 Tele-Meister

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    Noted - I ended up ordering some gavitt wire so I’m going to pull the old wire and redo it as suggested. In some diagrams I’ve found, the cap is soldered onto the tone pot and that’s it - is it wrong the way it’s currently configured?

    Thanks for all the help!
     
  15. TimTam

    TimTam Tele-Holic

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    That is the indication that you don't have a ground problem. Your guitar's grounded metal is doing exactly what it is supposed to do - grounding your noise-attracting body antenna.

    The fact that there is buzz when your body antenna is not grounded means that there is EMI in your environment. The fact that it is worse for this guitar means that the guitar is particularly subject to picking up EMI. It has single-coils, so that's part of the problem. It sounds like this guitar does not have grounded shielding in all cavities, and the pickguard ? If not, it needs it - electrically-continuous foil shielding (ie with conductive adhesive).

    It looks like you have a twisted pair for the output wires, which is good. Once you have good cavity shielding, it's probably not worth swapping that to shielded cable. Are the pickup wires twisted (or shielded) too ?

    After all that, what should be left is the noise of single-coils in a relatively noisy environment, reduced when you touch metal and/or turn down the gain.
     
    Last edited: Aug 5, 2019
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  16. kbold

    kbold Tele-Afflicted Silver Supporter

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    I recently had to replace a bridge grounding wire, due to the same issue as you have. At first I thought there was no bridge wire, but there was. I replaced the bridge wire and problem fixed. The original bridge wire was not plated (the strands were bare copper). The only explanation I had for this was that the strands had oxidised and were no longer making a good electrical contact with the bridge.

    i.e. Check that the strands on the bridge wire are silver colour, not copper colour. Replace if they are bare copper.
     
  17. NateD81

    NateD81 Tele-Meister

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    Yesterday my copper shielding tape arrived so I set to taping all the cavities and the pick guard. In my 50s classic series tele there was no shielding (tape or paint). As I finished each cavity, I checked for continuity and encountered intermittent continuity from the bridge plate to everywhere. I had encountered this issue in previous troubleshooting on this guitar, but figured that was probably my problem. I shielded the bridge cavity and made sure to connect it to the control plate cavity and low-and-behold, plug the guitar in and it’s whisper quiet. Not only is that buzz / clicking gone when I touch the strings, but the regular single-coil hum is essentially non-existent.

    It took about 6 dollars in copper shielding tape and a bit of irritation but I’m a happy camper now that it’s fixed. Thank you to everyone for your suggestions - looks like the folks who suggested looking into the bridge plate were right! Thanks again!
     
  18. EsquireBoy

    EsquireBoy Tele-Afflicted

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    I would say it proves the metal parts of the guitar are properly grounded.
    IMO if the buzz you are hearing is unusually loud, you should look elsewhere: noisy pickups, 60cycle hum sources near your guitar, etc.
    When you have a grounding issue, the hum/buzz does not fade when you touch the strings or other metal parts on the guitar.
     
  19. mherrcat

    mherrcat Tele-Holic

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    Check the wiring in your home. I have observed this occurring with my guitars at home, where I know I have 74 year old two-conductor wiring, but not at my office.
     
  20. Fuggle

    Fuggle TDPRI Member

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    Can you clarify what you mean by connecting it to the control cavity? How did you connect the bridge cavity to the control plate cavity?

    I'm having the same issue and want to try your fix.
     
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