TBX Tone Control Concern

[Belva]

http://www.guitarelectronics.com/product/WDUSSS5L1205

I'm putting together my latest project and find that I have nothing from the bridge & middle pups. I'm using the wiring diagram seen in this link.

I've tested the switch, the pups and even the output jack for continuity. All good. I also tested the pots and found that I have no resistance across the outside lugs on the top part of the TBX control (bottom when it's in the guitar). I'm not familiar with these pots and can't be sure if this is where the problem lies. The other part of the pot tests fine. And yes the grounds are all properly secuerd with no loops. Any thoughts? Thanks.

BTW I even disconnected the cap, resistor and jumper wire on this pot even though this shouldn't be a problem.

[mrbrown49]

Did you wire the little jumper btw the top and bottom section? Not that ius should matter. You should still get sound out whether the tone circuit was there or not, unless something is shorting the signal to ground.

 

Did you wire BOTH the first and last switch lugs to the V pot?

 

IIRC those should measure out like standard pots. There's nothing special about them other than being stacked and being wired in as they are.

[Belva]

I did wire in the jumper and wired the switch as you described. First thing I did was check to see if I'd mis-wired something. I'm beginning to think possibly grounding out may have been the problem. When looking at it again I noticed the lugs on the bottom of the 2 stacked pots were higher than the pot shell. So I did a bit of bending and re-routing of wires.

[mrbrown49]

You could try diconnecting that tone circuit. If you get signal, the problem is there somewhere. If you still don't, it's in the main wiring somewhere, probably a short around the switch or something like that.

[WRGKMC]

I agree, disconnest the tbx at the switch and get the switch functioning with the pups first, then go to the TBx and see whats happening there. If you get no continuity between the outer legs, try it from the center leg and the two outer legs as you sweep the pot. ot should go from zero to the maximum of the pot value.

 

What can happen is the solder blobs into the pot and shorts to the casing or can even go inside the pot. Until you get the pot readings happeningn then connecting it to the switch, only complicates the problem.

 

If you find the problem at the switch (which is what I suspect) then you may need to test the connections with an ohm meter and blueprint your connections.

 

The problems appear to be localized to the neck bridge and mid. If the neck is working then that hots OK. You just need to figure out why the the switch isnt distributing hot signal to the other two pups.

 

Its a problem with those 5 way switches. The one in the pic is a standard Fender switch but theres so many non standard switches out there and the only choice you have for some of them is to ohm them out to find all the on off conditions of the rotarty. If the switch is open, you can eyeball the connections of the plates when they move. For others that are sealed, you have to ohm them out.

[Belva]

I'll only use a standard Fender type switch because you can service them. It must have been a grounding issue. I rewired the switch, swapping sides and bent the lugs on the TBX pot so they were almost flat. I had to reroute the resistor to accomplish that, but it does work now. Sounds pretty good, too.