SL2H wiring help

[Cliff]

Hey,

I've got a problem with hum with my SL2H. If I touch the volume pot, pickup selector, pickups or jack (there's no tone control), the problem goes away. If I touch the bridge, the hum remains. So figure there must be a bad connection somewhere... duh!

I've been looking at the wiring schematic half-way down this page, and comparing it with what I see when I take the back off:

http://www.gad.net/Blog/2010/07/11/usa-jackson-soloist-sl2h-chrome-to-black/

In the actual wiring, it seems like the ground from the jack socket goes directly on to the back of the volume pot. The ground from the pickups, after going through the pickup selector, is also wired to the volume pot.

Then there are three more black wires, one coming from the connection to the trem block, and two coming from I guess the pickup cavity, and these are all soldered to a screw that goes into the wood. From reading elsewhere on the forum, I'm guessing the wood has conductive paint on it here - the gloss finish on the body and the rest of the inside of the cavity isn't present here.

I guess I don't really know what I'm doing, but I find if I touch a piece of wire to the back of the pot and the screw or conductive paint, the hum goes away.

Anyone got any ideas where the problem might lie?

Cliff

[dg]

Is there a wire going from that screw in the electronics cavity wall to the back of the volume pot or to the ground lug of the jack? That's what you're missing, and I think you figured it out for yourself. Solder that thing up and you're in business.

[tonemonster]

it sounds like a ground wire is not connected. dg pretty much said it all, just do like he said and you should be fine.

[Cliff]

Awesome. Thanks guys!

[Cliff]

So, a partial success this evening. Managed to pickup a soldering iron, solder and wire on the way home from work. Got the dining room table all prepped, got a good light source. Mentally prepared myself.

After taking the back off the control cavity, I poked around a little before getting to work, and before you know it I'd managed to break one of the other wires off the pot, thereby demonstrating to myself that I was quite capable, after all, of making things worse.

I watched a couple of YouTube videos on how to solder. They're a bit like the videos on sweep picking that I watched. Looks pretty straightforward, right?

So I struggled for an uncomfortably long time to tin the two ends of the connecting wire I'd cut. Eventually got some solder on there. Reading some of the posts from you guys who repair your own guitars, I'm reminded of Zen And The Art Of Motorcycle Maintenance: the idea that if you want to do a job well, you have to approach it with patience, love and diligence. This wasn't like that. I was so nervous, I couldn't wait to get it over with. Plus my wife needed the dining table for dinner. By the time I was resoldering the wire I'd snapped, the soldering iron was shaking in my hands like a conductor's baton at a recital of Flight Of The Bumble Bee.

I can't say I'm proud of the work - sorry, no photos - but I think I at least put the live wire back, and made the ground connection between the screw and the pot (and therefore the jack).

At first I thought it worked. Then I took my hands off the strings, and the buzz came back. I now have a buzz that I can cure by touching the strings or bridge, as well as the volume pot and pickup toggle as before. Actually, there's still a quieter buzz when I am touching one of these. So then I tried my Charvel, and it has the same symptoms, only the buzz is quite a bit quieter than with the SL2H.

So, have I suddenly become over-picky and this is just normal? Is the fact that it's quieter with the Charvel just a difference in the pickups (stock Jackson pickups in the Charvel, Humbuckers from Hell in the SL2H)? Or is there still a problem? I should also mention I tried the test with a Roland Cube as well as my Studio .22. With the Cube, even on the highest gain setting, the buzz/hum is still there, only quieter with both guitars. And now I think about it, how does that work? The Cube only has a two-prong plug, so doesn't that mean it's not grounded? I'd assumed the grounded wires on the guitar were connecting to the jack to be grounded at the wall via the amp. Now I don't think I understand

Any advice appreciated. As you can probably guess, if it involves soldering, I'm probably going to take it to a shop

Meanwhile, I'm off to practice my sweep picking. Now I know the noise isn't my fault...

Cliff

[javert]

I don't know if this is the problem, but it happened to me twice that Jacksons came wired wrong. Like in your case, there was a lot of noise, but the grounding at first appeared to okay. Turns out that somebody had mixed up ther terminals on the pots. So, you may want to check that the pots have been connected right. In case you didn't know, you can find wiring diagrams at the Seymour Duncan website. Here's one for 2 humbuckers, 1 vol, 1 tone, and a three-way switch:

http://www.seymourduncan.com/support/wiring-diagrams/schematics.php?schematic=2h_1v_1t_3w

[javert]

I missed the sentence about no tone control (do you have two volumes knobs then?). You can find the appropriate wiring diagram here:

http://www.seymourduncan.com/support/wiring-diagrams/

[tonemonster]

OK ..... if hands on the strings stop the buzzing, check the ground wire in the back trem cavity. make sure it is soldered to the trem claw. and check the other end in the electronic cavity. make sure that is soldered well. I bet that is the problem. try that and let us know how it goes.

[Cliff]

I think the hands stopping the buzzing is because of the link I made last night. The trem is connected to the screw on the inside of the cavity (this looks like a really solid piece of soldering). Now that I've connected that screw to the back of the pot, the buzzing goes when I touch strings or trem. Before that connection, that would have no effect, but touching the pot would fix the buzzing. So it seems to me the pot isn't grounded properly?

There's only one volume pot, no tone control. Thanks for the link Javert, but these are actually DiMarzio pickups. I cross-referenced the link you gave with this one:

http://www.dimarzio.com/media/diagrams/4Conductor.pdf

The wires coming into the control cavity from the pickups have some plastic shielding on them. When they split to go to the selector switch, they're covered in some rubber, but I can see from one of the pickups that the red goes where you'd expect, and the green and bare go to the grounded contact on the selector switch. According to the DiMarzio instructions, that should be it, aside from shorting the black and white wires together at the pickup. I haven't looked at the pickups themselves, but there's another pair of black wires coming from the pickups into the control cavity, and these are soldered to the screw. Which I've now grounded. This definitely seems wrong/different.

[dg]

The extra wires coming from the pickup cavities are to ground the shielding paint that's in those cavities. This is seen pretty often on J/C guitars. One common reason for the kind of ground issue that you have is a bad solder joint, and one of the usual culprits is the big blob of solder on the back of the volume pot.

[Cliff]

Thanks dg. I'll see if I can check this out over the weekend.