No sound... where's the error in my circuit?

[che_guitarra]

HI guys. I've recently resprayed my flying V, and culled off one of the pots in the circuit during the refurb. I like it simple - one volume and one tone is enough for me. Pickups are a pair of GFS Mean 90s - colour coding is white = hot, red = ground. I've paired the reds behind heat shrink and grounded to the vol pot.

I used a few SD schematic guides as reference. Not sure what i've done wrong, but i'm not passing an iota of signal. I've checked it over countlessly but i'm just not seeing what i've done wrong, so hoping to cast some fresh eyes over these pictures to advance my troubleshooting. DMM movements suggest all components are fine, but can't really prove without desoldering and testing in isolation. Pics have had their contrast enhanced for visual benefit, but I can confirm no cold solders either.

Any ideas?

 

[ehdwuld]

Re: No sound... where's the error in my circuit?

Do you have a meter
If so check hot to ground on each pickup
Then set the switch to each pickup set if you get the same reading

Then check your pot
Center to ground and hot to ground


*(Sent from my durned phone!)*

 

[Funkfingers]

Re: No sound... where's the error in my circuit?

Jack socket. You have the signal connected to the sleeve (ground) terminal and the guitar grounding connected to the tip (signal) contact.

 

[greekdude]

Re: No sound... where's the error in my circuit?

Hmm grab the VOM and start testing for continuity. Check those paths :
- pups -> switch input
- switch input -> switch output
- switch output -> vol pot out
- vol pot out-> jack hot

also check your grounding : bridge to every element supposed to be grounded

also check your pups resistance, is it within manufacturer's limits?

 

[ehdwuld]

Re: No sound... where's the error in my circuit?

Jack socket. You have the signal connected to the sleeve (ground) terminal and the guitar grounding connected to the tip (signal) contact.

So the volume should work backwards then? [emoji4] [emoji4]

*(Sent from my durned phone!)*

 

[Funkfingers]

Re: No sound... where's the error in my circuit?

The signal goes to ground via the instrument cable.

The ground to input run might generate some noise through the amplifier.

 

[greekdude]

Re: No sound... where's the error in my circuit?

Jack socket. You have the signal connected to the sleeve (ground) terminal and the guitar grounding connected to the tip (signal) contact.

you nailed it.

 

[Funkfingers]

Re: No sound... where's the error in my circuit?

I simply looked at the photographs and spotted a simple oversight.

 

[GuitarDoc]

Re: No sound... where's the error in my circuit?

Soldering looks fine. As was said, your jack is wired backwards. Check your switch as well. Looks like you've got the lead from the switch connected to ground, and the ground from the switch connected to the vol pot lead lug.

You have soldering skills, but you're not paying attention to what you're doing.

 

[Funkfingers]

Re: No sound... where's the error in my circuit?

Check your switch as well. Looks like you've got the lead from the switch connected to ground, and the ground from the switch connected to the vol pot lead lug.

Correct.

On those right-angled "SG" type Switchtcraft selector switches, all of the contacts are at the same end of the switch body. The ground connection "eye" (the thick, solid metal loop) is directly above the two thin metal terminals that are bent together and soldered to carry the signal output.

On the OP's guitar, the white insulated wire from the volume pot goes to the two bent together contacts. The yellow insulated solid core wire goes to the selector switch ground lug. (Good luck soldering that!)

 

[kramersteen]

Re: No sound... where's the error in my circuit?

I simply looked at the photographs and spotted a simple oversight.

You are of a higher power.

Yeah i worked that out about a switchcraft switch on the virtus wiring haha. Its obvious looking at it now but yeah if you have only ever used the other type of toggle it can trick you,

 

[che_guitarra]

Re: No sound... where's the error in my circuit?

Beautiful. Thanks guys

 

[che_guitarra]

Re: No sound... where's the error in my circuit?

So the output jack isn't the only problem. But for the life of me I can't see any other circuit errors. I've compared it to two or three 2xP90 1xV 1xT diagrams but there's no difference between any of them, as expected.

My next guess is i've got the pickup taps wrongly wired. GFS colour coding suggests white = hot, red = ground, shield = ground. As such i've got red and shield soldered to the back of my volume pot - whites going to each side of the pickup selector. And sure enough i'm not getting continuity through the pickups when I measure white to red. I'm only getting continuity through the pickup when I switch the pickup selector. Does this mean i've got red and white the wrong way around? Or am I dealing with an unlikely double pickup failure? My thoughts are that I should be seeing the meter LED spike a littleon my interface's LED when I switch about the pickups, but i'm seeing nada, zilch, zip.

 

[Funkfingers]

Re: No sound... where's the error in my circuit?

I can't see any other circuit errors.

Have you corrected the selector switch error yet? (The yellow and thick white insulated wires.)

 

[che_guitarra]

Re: No sound... where's the error in my circuit?

Ahhhh, gotcha - they need to be flipped? This is my first encounter with these Gibson pickup selectors - they're not very intuitive, lol, but I guess assumption is the mother of all ignorance too. I can see the switches layered construction now.

Just to confirm - the ground lug is between the pickup hookup lugs, and the lug below it is the switch's output?


Thanks again.

 

[che_guitarra]

Re: No sound... where's the error in my circuit?

We have lift off Thanks for the troubleshooting help guys.

 

[GuitarDoc]

Re: No sound... where's the error in my circuit?

There is nothing wrong with "assumption" as long as it is based on actual observation, facts, and reality.