I bought this item in pieces on ebay through a liquidator- the body /neck unit( with the top of the headstock cut off). The second purchase was the electronics - pickup harness, jack and switch. I was assured that everything worked. When Igot it all assembled- the neck pickup never worked, and now the end jack has a buzz that goes away if you touch it. These are not necessarily related...
My question is- how do i find the source of the problems? Can I test the (neck ) pickup and the switch in place? If you've ever coaxed the electronics of a semi -hollowbody into place , you know it's not that much fun.
What are the most likely issues? I was told that the 3 way selector is seldom a problem- true? , or one guy's opinion?? How do I test the components in place? I'll pull them if I have to- would prefer not to do so! Thoughts?
You will have to gut the instrument to measure this stuff - it's shorter in the long run than taking shots in the dark - anyway , you had the wiring harness separate so you know how it went in, right, so it can come out the same way.
Download a generic wiring diagram, test security of all wires with some tweezers to see if any are just hanging on by a thread, check all earth wires for security and that the jack is wired up with the earth to earth and hot to tip. Get a cup of coffee and take some deep breaths.
Drop the hot wires off the pot tags and measure the individual resistance (about 5 to 8k is ballpark) to a known ground (usually the back of the pot - but make sure as this guitar probably has an earth off somewhere by the sound of the problem.
Then connect the individual pickup hot wire directly to the hot output on the jack (individually) using a jumper or just solder it on temporarily - direct wiring cuts out the pots and the switch and make sure both pickups are working relative to the jack earth. Check the pickup earth to the jack connections at this point also.
If all good, check your selector switch earth wire by putting a meter across the bare metal exposed ring nut outside the guitar (if it is a Switchcraft switch or similar) and the earth side of the output jack (should show a short circuit - that is ; continuity) and it that's good check your individual switch feeds from the pot tags to the output jack for similar continuity (make sure the switch is in the correct position to check these separately. If the selector switch is a box shaped piece of junk or made anywhere in Asia, throw it away and put in a Switchcraft unit regardless of whether it works or not. The theory that selector switches seldom give problems is as reliable as Yetti sightings, Ditto the jack - replace it with a SC unit and never worry again.
Then, if the problem persists, drop most of the wires off the pots and check your pots for end to end and wiper to end resistance - about 500k and variable respectively - making sure your pots don't "switch off" (open circuit) at the extremes of the wiper travel
This is a quick check of most of the important things - if you still have no joy maybe best if you take it to a guitar tech who has some kind of qualification with electronics/wiring. Chances are pulling offa all the wires and re-soldering them (especially in the right places) often fixes the problem. Pickups also fail more often than one would like to believe.
Good luck. Rusty.
Caveat emptor...ESPECIALLY when it comes to e-bay. As we all know "Worked the last time I used it", is code for "It's got problems or is dead".
Given the nature of your issues, which are quite common with import electronics, you'll most likely have to pull & completely rewire the harness. That's the only way to assure everything is right and there are no broken or cold solder connections.
You can "test" the DCR in the pickup by putting the selector switch in the position of the PUP you want to test, turn the volume & tone controls to 10, plug in a cable and measure the DCR with a VOM or DMM at the plug end of the cable. If it reads something like 5.5K-10K, you should have a working pickup.
If the problem is in the switch ( & switches definitely can be the problem and their issues are usually caused by poor solder connections, dirty contacts or bent "leaves" caused by mishandling), this method of diagnosis will not reveal it.
We all hate to dig into semi-hollowbody guitars, but the symptoms you describe, I think, call for a complete rewire. At least that's what I'd do on my bench.
Best of luck (:
Thanks Paul, we seem to have similar formative years here. Rusty.
If I may add 3rd harmony to the Paul & Rusty chorus, let's assume you have pulled the harness. Make your self a "template" of where the controls go. For one-offs I'll do a rubbing of the guitar top onto paper and transfer that to cardboard. Punch out the holes and you've got soemthing to hold the pots & switch. Certainly replace all the cheap components (everything except the pick-ups) while you have it out. I might even replace the wiring depending on how cheesy the factory stuff presents. If you're testing by tapping the pick ups with a screwdriver, make sure you get strong sound with the tones turned down. An open pick up can still make noise (somewaht anemic) but will fade out totally with the tone rolled off. You don't want to discover that once you've re-installed the harness. Also, make sure you don't short something out (via exposed shielding) when putting it back in the guitar.
After all, anything worth doing is worth doing over and over again.
Check the pickups per Rusty. If they work, scrap everything else and start over. Switchcraft parts and CTS pots are cheap, compared to time. Use new wire. This removes any bad joojoo that may be present.
Sure sounds like it Rusty. (: I got my earliest "guerrilla" diagnostic training in the trenches in the '60's & 70's between sets. Ah, those were the days. Our only professional concerns were great tone, reliable gear and worthwhile music. If you carried a soldering pencil & spray cleaner in your kit (& knew how to use them), you were considered a god.
To recognize & echo Chris J's advice.: To me, it's more cost & time effective to completely replace the pots, wiring, switch & jack (ONLY Switchcraft as Rusty advises) that to diagnose the exact problem with passive components of, at their very best, marginal quality.
I might as well throw in my mantra advisory that if the OP doesn't have expert soldering technique & skills, take it to a tech that does.
See ya guys (:
I do what Christian does when possible. The whole works while you got the guts out. One minor caveat, you might need to slightly enlarge a mounting hole, or four.
Sorry, guys, I've been off the net for a while. OK, You've coninced me , out it comes! I appreciate all the help and detriled responses. I'll have to print all this out and make myself a checklist. I'll let you know how it goes, but I may not get to it for a while. Thanks!