Strange Wiring Question

[Brow]

Hey guys.

I'm in the process of repairing an Epi LP Special for a local school and have noticed something quite strange while trying to repair it.

I found the problem in the wiring and repaired it, but the strange thing is that whenever the switch isn't physically bolted to the guitar, the output is much higher!

When the switch is 'floating' inside the guitar it's output is as it should be, but whenever I put the switch through it's hole in the top of the guitar and bolt it into place, the guitars output drops to a whisper.

Does anyone know what could be causing this and how i could fix it?

Thanx for any info.

Craig

 

[Dave Z]

Re: Strange Wiring Question

sounds like a grounding problem maybe - is there conductive paint in the cavity? If so try scraping away around the switch hole.

 

[BachToRock]

Re: Strange Wiring Question

Sounds like the body of the switch is grounding out the signal... is the control cavity painted with shielding paint?

 

[Fritz6]

Re: Strange Wiring Question

Is the hot lug or wire touching the shielding when the switch is bolted down?

 

[Brow]

Re: Strange Wiring Question

Thanx for the posts guys.

There's no shielding paint in the cavity, so it can't be that.

I've checked around the hole that the switch sits in, and it doesn't seem to be catching on the switch at anypoint.

I'll double and triple check everything, and if I still can't find the problem then I'll try a new switch

Thanx for the posts.

Craig

 

[HolyDirt]

Re: Strange Wiring Question

Are you sure the switch doesnt move a wire and short the wire out when you mount it? The switch could be attached to a wire that has a little bit too much bare-ness on a terminal.

 

[octavedoctor]

Re: Strange Wiring Question

What i have found with some of the new Epiphone switches is that the contact surfaces are not very good. It may be that microscopic movement in the frame is causing the contact leaves to pull apart slightly.

Also, the three screen wires soldered to the switch frame can sometimes develop loose strands which short out against the edges of the contact leaves betwen the paxolin spacers.

Try resoldering every joint and cover any exposed earth wires with heat shrink tubing.

 

[Brow]

Re: Strange Wiring Question

Thanx for the posts guys

I'll checl all the solder joints on the switch, and tie up any loose strands

Hopefully that'll solve the problem. If not, I'll fit a new switch

Craig