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Silent Les Paul (likely switch problem)

papabear16

Member
Joined
Aug 23, 2020
Messages
38
I'm the newbie with the recent post on the Peter Green mod. I finally got around to rewiring my Epiphone Les Paul today. I thought I had it all done—and it is silent. I need help figuring out what's wrong. I hope you don't mind a long post, but I want to give you all the information that I think might be relevant.

First, a little background. I purchased a prewired harness from StewMac that came with a wired switch and pots and caps wired '50s style, which is what I wanted. I had to make two changes to this wiring configuration to install the new hardware. First, because of the way the ground wire connected the pots along with contours of my control cavity, the tone pots were forced into a position where the lugs were difficult to access. So I clipped the ground wire neatly between the two tone pots and resoldered that wire to the back of each tone pot in a position that let me rotate the pots as I wanted. I tested for continuity with my multimeter and all seems good, all the way from the neck volume pot around to the bridge ground wire (soldered ot the back of the neck volume).

The second modification I had to make is, I worry, the culprit here. I discovered that the switch from StewMac wouldn't fit in my Les Paul—the shaft was too short for me to get a nut on it. I have no idea how to wire a switch, but I could see that the tabs on the new switch and on the old switch lined up. So I unsoldered the new switch and resoldered the old to the new wiring, keeping track of what goes where. Looking at how-tos online, I sure think I did it right.

But something is off, as I said, because the guitar is silent. I've used my multimeter to do a bunch of connectivity checks, and here's what I've leanred.

1. The back of the bridge volume is connected to the bridge tone, the neck tone, the neck volume, and the bridge ground wire. I think this is right.

2. The braided shielding on both the neck pickup wire and the neck switch wire, both soldered to the neck volume pot, are also part of that same ground circuit. I think this as it should be.

3. The braided shielding on both the bridge pickup wire and the bridge switch wire, both soldered to the bridge volume pot, are also part of that same ground circuit. I think this is at it should be.

4. Both neck and bridge capacitors ARE pare of the ground circuit. And here I think is the problem, because I'm pretty sure that's not right.

5. I opened the switch cavity back up and pulled out the switch. The multimeter reveals the following:

a. With the switch in the neck position, the neck out and the ground are connected. Nothing else is, including the jack lug to anything.

b. With the switch in the moddle position, the neck, bridge, and ground are all connected. And nothing is connected the jack lug.

c. With the switch in the bridge position, the bridge out and the ground are connected. Nothing else is, including the jack lug to anything.

This leads me to believe that either something is wrong with switch (which gave me no problems before) or something is wrong with the bundle of wiring leading into the switch. Because it sure doesn't seem right that the neck or bridge are ever connected to ground, or that the jack lug isn't connected to anything. I've also looked closely and can't see any wires or even filaments connecting the bridge, neck, and ground lugs.

Any ideas what is going on here? I'm very grateful for any advice.
 

papabear16

Member
Joined
Aug 23, 2020
Messages
38
Some more information. I unsoldered the switch itself. All the wires that should be connected seem to be, and there are no grounds that hsouldn't be there. THis made me think that the problem is the switch.

When I test the switch in the middle position, both volume lugs are connected to the ground, and nothing is connected ot the jack lug. That sure seems wrong to be. So I grabbed the new switch (that I can't use) that came with the harness, and it works the way I expected it to. For example, in the middle position, both volume lugs are connected, and their connected to the jack lug, but none of them are connected to the ground. That sure seems like it must be right.

I have looked everywhere for solder that shouldn't be there. I can't find any. Something is wrong with the. So barring any other great ideas, I'll order a new and and that should take care of the issue. I hope.

Any insights are welcome.
 

somebodyelseuk

Well-known member
Joined
Jun 10, 2020
Messages
454
Some more information. I unsoldered the switch itself. All the wires that should be connected seem to be, and there are no grounds that hsouldn't be there. THis made me think that the problem is the switch.

When I test the switch in the middle position, both volume lugs are connected to the ground, and nothing is connected ot the jack lug. That sure seems wrong to be. So I grabbed the new switch (that I can't use) that came with the harness, and it works the way I expected it to. For example, in the middle position, both volume lugs are connected, and their connected to the jack lug, but none of them are connected to the ground. That sure seems like it must be right.

I have looked everywhere for solder that shouldn't be there. I can't find any. Something is wrong with the. So barring any other great ideas, I'll order a new and and that should take care of the issue. I hope.

Any insights are welcome.
The Epiphone switch is a copy of the Gibson/Switchcraft switch, BUT it's not an exact copy. If I remember correctly, it wires up differently. Switch is probably okay, you just need to wire it the right way.
Not certain, but I think the ground and live output are the opposite way round to the Switchmaster. If I find out for certain, I'll post.
EDIT: On the Epiphone switch, your pickups and jack should be wired to the three tags on the same side of the switch, with the grounds soldered to the tag that is part of the switch frame on the opposite side.
On a Switchcraft switch, the jack and grounds are the opposite way round.
 
Last edited:

papabear16

Member
Joined
Aug 23, 2020
Messages
38
The Epiphone switch is a copy of the Gibson/Switchcraft switch, BUT it's not an exact copy. If I remember correctly, it wires up differently. Switch is probably okay, you just need to wire it the right way.
Not certain, but I think the ground and live output are the opposite way round to the Switchmaster. If I find out for certain, I'll post.
EDIT: On the Epiphone switch, your pickups and jack should be wired to the three tags on the same side of the switch, with the grounds soldered to the tag that is part of the switch frame on the opposite side.
On a Switchcraft switch, the jack and grounds are the opposite way round.

Ah, that makes sense! Okay, I'll get the soldering iron back out. The switches looked so similar that it never occurred to me that the lugs might be different! Thank you so much!
 
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