SG Muse makes noise (maybe ground circuit?)

Discussion in 'Epiphone Guitars' started by IvanS, Nov 24, 2021 at 11:37 AM.

  1. IvanS

    IvanS New Member

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    Hi everyone.

    First time user here.
    I just got an SG Muse but noticed there's a noise coming from the guitar that stops when I touch a pickup. This makes me think this is coming from the ground circuit. I remember reading some time ago that this particular model of guitar had such issues, but can't find where I read it or how to actually fix it.

    How can I figure out how to fix this? I've changed pickups to other guitars before and do own a multimeter (but used it in college and never again, so I forgot how it actually works or what values mean). I checked the control cavity and the ground cable seems to be correctly soldered to the back of a tone control and seems to be securely soldered to the pickup cavity (I haven't actually checked, but just tried to pull it gently to see if it was at least holding to something and it seems it is). The rest of the controls are kind of different to what I've seen before (being push/pull), so I wouldn't even know where to start.

    How would you fix something like this?

    Thanks!
     
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  2. Raiyn

    Raiyn Well-Known Member

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    Test procedure:
    1637779770314.jpg
    The setting where it makes a noise when you touch the leads together.

    Check for continuity between the bridge and the sleeve of the output jack. If it beeps, you have a connection. If not that's the problem.

    If there is a connection, switch to your resistance scale and see what you have.
    1637779866769.jpg
    If there's much more resistance than there is probe to probe, this can also be a problem. If the resistance through the wire is more than through you, the current will go through you.

    Under warranty: Take it back to the shop and explain the situation. This is the best advice I can give to someone who doesn't know what they're doing. Something may seem simple, but I've seen the results of "How hard could it be?" Also, if they screw it up, it's on them - you're not the guy.

    Voided warranty? Personally, as a modder, I'd be yanking the whole thing apart, adding shielding etc., but there are less fun extreme measures to explore first.

    You could start by reflowing the bridge ground solder point, if that doesn't work, buckle up.

    You'll want one of these:
    [​IMG]
    https://www.amazon.com/AmplifiedParts-4320252326-Knob-Bushing-Puller/dp/B01CKCWID2

    Yes, there are other methods, but the possibility for a gooch is much higher - particularly on a thin body like an SG. If you value this guitar, get the tool. This is one of the very few times where I'd ever suggest pulling a bushing, so you want to get it right.

    Using your tool, pull the lower bridge bushing. Next, remove the bridge ground wire from the back of the pot and the hole. Desolder from the pot.

    Cut a new piece of wire (I like 20 AWG) long enough to reach the pot while sticking out the top about two inches or so. You're trying to build in a bit of slack for the next bit so you could actually just feed the loose end of your coil from the cavity side and cut to length once you establish what you need if that's your preference.

    Next strip a length of wire long enough to reach the bottom of the hole plus enough to grab with a pair of pliers or vise grips and not interfere with you tapping the bushing back in with a hammer. The idea here is that if it's all the way up the bushing and sticking out under the shoulder - you have as much opportunity for contact as possible. By holding on to the wire, you also prevent it from being pushed down in the hole and potentially causing issues with the bushing replacement or deforming more wood than necessary.

    Once you have determined how much stripped wire you need, twist and tin the exposed wire. It keeps the whole deal neat especially if you use the baby fine strand stuff I use.

    Reintroduce the ground wire to the hole. Ensuring the bare wire is all the way to the bottom of the hole grasp the top end with your pliers.

    Align your bushing to the flute pattern pressed in the wood as best you can and start tapping the bushing home using a plastic or taped over hammer (painter's or electrical works fine, use a couple layers). As a reminder, you want wire sticking out under the shoulder.

    Once the bushing is reseated, cut the excess wire off using a pair of flush cutters right at the shoulder.

    All that remains is to cut the wire to length inside the cavity, strip back a bit, twist, tin and solder on the back of the pot.
     
    Last edited: Nov 25, 2021 at 2:08 PM
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  3. IvanS

    IvanS New Member

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    Sounds like something I would like to learn to do.



    My only issue would be the tool, though. Where I'm from getting that tool is a fifth of the price of the guitar.

    I found this video in YT with the title
    "How to Remove Tune-O-Matic Bushings (in 53 seconds)"
    (I was't able to post the link the forum bot thinks it's spam)


    The procedure is to remove the bride post, drop a screw head-first of similar length and screw the post in back again. The bushing will come out like magic.


    Sounds... reasonable. What do you think?


    I've been watching videos about how to apply shielding and such, and it doesn't seem difficult and actually very useful. I might apply that as well, and then to my MiM Strat.



    Thanks a lot!
     
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  4. BGood

    BGood Well-Known Member

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    That is how I do it, easy peasy.

    Bushings.png
     
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  5. IvanS

    IvanS New Member

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    Awesome! I'm gonna have so much fun with this project :)
    Thanks BGood and Ralyn!
     
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  6. Raiyn

    Raiyn Well-Known Member

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    There are other cheaper sources.
    You clearly didn't read this:
    [​IMG]
    What the Jean's picture or the video don't show you is when the bushing is particularly tight (or glued) and you push the bolt out through the back of your guitar. I've done it - you don't want to be that guy. This method is fine for an LP, but a thin guitar like an SG is way more risky.

    I'm going to repeat my earlier advice.
    Under warranty: Take it back to the shop and explain the situation. This is the best advice I can give to someone who doesn't know what they're doing. Something may seem simple, but I've seen the results of "How hard could it be?" and "easy peasy" Also, if they screw it up, it's on them - you're not the guy.


    Learn on a junk guitar, not a brand new Muse. Watching a YouTube video doesn't make you an expert.
     
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  7. IvanS

    IvanS New Member

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    Not in my country, unfortunately. That's why I tried to look for alternatives.
    Thanks for the warning.
     
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  8. BGood

    BGood Well-Known Member

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    To find the right setting for continuity on your multimeter, have the poles of the tester touching each other and rotate the dial. You'll see values on the screen. If it's analog, the pointer will move.
     
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  9. The Convert

    The Convert Well-Known Member

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    Good point. Also not always super effective on guitars made of softer wood like basswood. Just makes a bad situation worse.
     
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  10. IvanS

    IvanS New Member

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    I was lucky and reflowing the tone pot was all there was to it. Thanks everyone!
     
  11. Raiyn

    Raiyn Well-Known Member

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    Awesome. Best news I've heard today.
    :cheers:

    Yup. You don't want to be that guy.

    Welcome back by the way.
     
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