Terrible grounding issue/js30RR

[Betrayer]

need someone knowledgable with the wiring and inner workings of this guitar.
I picked it up a year or so ago with intentions of upgradeing it somewhat.
never got around to doing much to it, it sounded great as it was anyway.

Although lately it has been producing a terrible hum, or buzz, only when the gain is up very high and it gets very quiet when I touch, the strings, bridge,switch, vol or tone pots.
it is unplayable.
I have put a seymour duncan sh-8 invader in the bridge and rewired the whole guitar.

there are wires underneath the pickups, connected to o ring terminals screwed into the wood.
there is also a wire going to the bridge. (apparantly working since the buzz gets softer when touching the strings)

and there was a o ring terminal screwed inside the cavity with all common grounds connected to it. I have moved these all to the volume pot with no effect at all.


everything is ground to the volume pot, so there are no ground loops..

It is not the cables or the amp. Have tested both extensively.. (problem is with this guitar only)

so here I am with an unplayable guitar.. Any ideas or help appreciated.

Chris

[rjohnstone]

Definitely a grounding issue.
Sounds like you may have a cold solder joint somewhere.
You could also have a break in one of the ground wires (internal break).

I would recommend moving all the ground wires back to the screw on the cavity wall.
This does two things. It centralizes all the grounds and then sends one common wire to the volume pot. It also grounds the system to the shielding paint used in the electronics cavity and pickup cavities.

First thing though is test all your solder joints and leads and make sure there are no internal breaks.
You could have also cooked the volume pot when soldering to it. The JS series use some really cheap pots. Spend the extra $$$ and get some CTS replacement pots. They run like $5 each.

[Betrayer]

Ok I had the electrician at work resolder it all for me, much better but it is still there somewhat.

I think he soldered all the grounds to the volume pot and 1 lead to the cavity from there.

The volume pot is burned however, its stuck wide open i assume. I cant turn it down, Ill stop and get a cst on the way home from work but not sure if I need longshaft or short shaft?
I assume long? since there is no pickguard?

thanks!

[rjohnstone]

Long shaft pots are for Les Pauls or other archtop bodies.
You need this pot.

http://www.guitarelectronics.com/product/CPC500B/CTS_500K_Linear_Taper_Guitar_Volume_Tone_Control_Pot.html

[Model1VH2]

Ok I had the electrician at work resolder it all for me, much better but it is still there somewhat.

I think he soldered all the grounds to the volume pot and 1 lead to the cavity from there.

The volume pot is burned however, its stuck wide open i assume. I cant turn it down, Ill stop and get a cst on the way home from work but not sure if I need longshaft or short shaft?
I assume long? since there is no pickguard?

thanks!

Sounds like, by grounding everything to your volume pot, your "electrician" got it too hot and fried the potentiometer.

Since you now have to replace your pot, I would simply take all of your individual ground wires and solder them all to a lug coming off your input ground (aka: Star Grounding).
This should solve any ground issues you may have.
It should also save you from frying another pot.