Problems with new les paul style wiring.

[oldbuilder]

Hello I am a novice luthier and am having problems with my wiring. This wiring is new all components are new.   when I hook up to an amp, I dont have any sound at all from the center position {3-way switch. }  It also seems in rhythm or treble positions, both pickups are active?   I have checked the switch, seems to be working properly, resoldered the wires to ensure connections are good. Again it does not have any sound from the middle position, which should be both pickups???  Any help will be most appreciated! Thanks

[unreg]

May 28, 2023 9:21:03 GMT -5 oldbuilder said:

Hello I am a novice luthier and am having problems with my wiring. This wiring is new all components are new.   when I hook up to an amp, I dont have any sound at all from the center position {3-way switch. }  It also seems in rhythm or treble positions, both pickups are active?   I have checked the switch, seems to be working properly, resoldered the wires to ensure connections are good. Again it does not have any sound from the middle position, which should be both pickups???  Any help will be most appreciated! Thanks

[EDIT]Oh yes, welcome to GN2![/EDIT]


Well, yes middle switch position of a three-way switch most likely is for bridge and neck pickup. But, that is solely dependent on how said guitar is wired. Could you reply with the type of guitar and an image of the control cavity? (That would help your question to be answered. But, maybe someone will understand the problem and provide a solution without the image of your wiring?)

[oldbuilder]

This is a guitar my older brother built when he was 15, he is now 78. Was built in 1960 and a few years later he went to Vietnam. He sent it to me to upgrade it. It only had 1 top mount silvertone pickup.
 The wiring is epiphone pro buckers with plug and play system. The middle position has no sound and either the rhythm and treble seem to have both pickups active??? Thanks

[stevewf]

Wow, he made that at 15 years of age! Pretty! But the PC boards on the volume pots must have been added later, no?

OK, looks like there are push-pull switches for selecting the pickups (and not the usual LP-style 3-way selector). I'd say the PC boards throw lots up into the air, since we can't tell from the photos what pickup lead gets attached to what terminal on the control. I'm left with the basics:

- When you test the middle position, are both volume knobs on?
- What's 'middle position' on this guitar? I guess it's either both P/P switches up or both down... and without knowing the PC board, this question is less critical.
- Is "not have any sound" really silence, or is there any sort of hum at all from the guitar?

[oldbuilder]

I added the drop top to it and also added the electronics. He found an old silvertone guitar at a dump and used those electronics a surface mount pickup and one volume/one tone is all it had. It was just plain hard rock maple when I got it, very thin, so I added woods front and back to get the proper thickness. The pickups now came in a wiring package, just having problems figuring out 3 way switch problem.

[unreg]

Very cool that you’re fixing it for your brother sir! He built it at 15?! WOW!

May 28, 2023 13:01:32 GMT -5 oldbuilder said:

The wiring is epiphone pro buckers with plug and play system. The middle position has no sound and either the rhythm and treble seem to have both pickups active??? Thanks

In your pics, I don’t see the 3 way switch. But, you all seem to have 4 pots… a volume, tone, rhythm, and treble? Are two of the pots push-pull? It seems that way, to novice me at least.

If so, then you’re saying that both pickups seem to work when the “rhythm” and “treble” push-pulls are active?

The point of my reply is to recommend you test each pickup with the screwdriver tap test. Then we would be certain that both pickups are working. (I’ll be back with a link to that screwdriver tap test thread in the reference section.)

EDIT: guitarnuts2.proboards.com/thread/4938/testing-phase-screwdriver-pull-test

And sorry for my response… it’s evident stevewf actually knows things. Didn’t see his response until after posting this.

[oldbuilder]

There is a slight hum when switch is up or down and both pickups have power, but in the middle position, no hum or sound at all.

[oldbuilder]

This is what it looked like when I got it. The 3 way switch upon inspection is working as it should in how the switching operates. the push/pull operated but the problem is in the middle position on the3 way switch, there is no sound at all I have done the tap test, that is how I test it at the moment.

[unreg]

May 28, 2023 16:36:41 GMT -5 oldbuilder said:

This is what it looked like when I got it. The 3 way switch upon inspection is working as it should in how the switching operates. the push/pull operated but the problem is in the middle position on the3 way switch, there is no sound at all I have done the tap test, that is how I test it at the moment.

So, you added a potentiometer? And, one of the now 4 knobs turns a rotary 3 way switch?

[oldbuilder]

No it has a standard 3 way switch . I may have found the problem. I checked the wires from the 3 way switch and the ground has no continuity. It must have been broke in shipping or I may have broken it, I am not sure!! I have ordered a new switchcraft switch with new wiring so in a week or so, I hope!!! it should be here. I was getting a lot of hum from both pickups in the rhythm/treble positions so it may be this grounding issue.

[stevewf]

I'm starting to catch on to what the guitar is. In any case, it's cool to see a guitar created by a 15 yr old that's still alive and evolving 60+years later.  The plug/sockets open up a world of modularity, if the work's put into other modules. A drawback is that it's hard to see what's going on without documentation.

For example, it's a mystery to me what the push-pull switches do (or are meant to do); could be a range of things, like phase swapping, series/parallel, pickup splitting, broadbucking...  Nevertheless, I think we can agree that Middle Position of the selector switch shouldn't result in silence.

Here's what I think I know about LP 3-way switches: There should be three signal-carrying wires: one that receives the Neck pickup's output; one that receives the Bridge pickup's output; one that sends the signal onward to (or toward) the jack. In this type of switch, there's no role in the signal chain for a ground wire. A ground wire could be part of the noise shielding, but its breakage would not normally cause silence (unless by that breakage, a loose shielding wire were causing a short circuit). So I'd advise to look at whether a broken shielding wire is causing a short, and if it's not, then look elsewhere. Anyway, refreshing the whole switch setup with the one you've ordered will give you a chance to clean up any problems.

Keep us up to date, and don't be shy with the details about the guitar, like what the push-pulls do, and how you put the top and bottom on the guitar body, and all that!

[newey]

OK, I'm all confused here. The photos seem to show a guitar with 4 pots and no 3-way switch of any type. Two pots seem to be push pulls. But as noted, it's impossible to know anything without knowing the innards of those push/pulls.

But if the problem is the three-way switching, where's the switch?

[reTrEaD]

May 29, 2023 7:35:06 GMT -5 newey said:

But if the problem is the three-way switching, where's the switch?

The edge of its washer is visible in the lower left of this image:



But there's no wiring diagram or even a photo of the wiring to the switch so vital information was not given.

[stevewf]

May 29, 2023 7:35:06 GMT -5 newey said:

OK, I'm all confused here. The photos seem to show a guitar with 4 pots and no 3-way switch of any type. Two pots seem to be push pulls. But as noted, it's impossible to know anything without knowing the innards of those push/pulls.

But if the problem is the three-way switching, where's the switch?

I think we've been given a mix of photos along the guitar's evolution, with the newer photos in the original post, the third of which gives a tiny glimpse of the 3-way switch. If I'm correct, subsequent posts show earlier incarnations of the guitar.

Back to the trouble as reported: whenever my project makes no sound (meaning also zero hum), my first thought is: Short-circuit to ground. Somewhere downstream from all the activated pickups, a hot wire and a ground wire are joined. Could be joined by wires accidentally touching, by having soldered them together by accident (not in the design) or on purpose (bad design or intentional kill).

Parallel: With our limited view, it's tempting to assume that the two pickups are strictly in parallel with one another. In a parallel setup, "downstream from all the activated pickups" is equivalent to "downstream from any one or more of the activated pickups". Since you mention that each of the pickups when activated in isolation don't suffer this problem, it seems to rule out that the pickups are in parallel with one another... or that they're wired in a way that I haven't encountered.

Series: In a series setup, "downstream from all the activated pickups" is equivalent to "downstream from the last of the activated pickups". But this should also manifest when the downstream pickup is selected in isolation; since this doesn't happen, it seems to rule out that the pickups are wired in series with one another... or that they're wired in a way that I haven't encountered.

So from what I can see, the trouble lies in the wiring of the 3-way itself. As mentioned earlier, a ground wire normally has no role in the signal path in a 3-way switch. If you've got a ground wire on any of the 3-way's signal path terminals (and there should be exactly three of those), then I'd start there. A ground wire could optionally be soldered to the body of the switch for noise reduction, but that wire should not be soldered to any of the 3 signal-bearing terminals, and the ground wire should not be left loose where it could accidentally touch a signal wire.

[newey]

May 29, 2023 10:54:03 GMT -5 stevewf said:

the trouble lies in the wiring of the 3-way itself.

My first thought was a mistake there, perhaps mistaking the common lug for the frame ground lug.