Where to look for a problem with new wiring producing no sound

[RobRed]

Hello:

I just rewired a knock-off hollow-body Tele. It had gotten wonderful reviews online, but when I got it home, it was just terrible. I have to wonder whether the manufacturer and family and friends were responsible for the wonderful reviews. I plugged it in and got the worst hum I've ever heard from a guitar in my life. The fret ends were so sharp, I could have cut the skin of my left hand playing the thing. I could not produce any musical sound worth listening to on it.

My response was to decide to rewire it and upgrade it. I got new pickups. I got a wiring kit with a four-way switch. I got heavy brass bridge saddles. I got tools to dress the frets, which were just awful. Anyway, I am confident of my soldering technique, followed the schematic carefully, cautiously checked all connections by gently tugging on them, and all appeared fine, but when I got it all put together and plugged it in, there was no sound through any of the 4 pickup selectors.

The instructions said that if neither a metal control plate or some kind of shielding plate was being used, the tone pot needed to be grounded to the volume pot. With the horrendous hum when the guitar was new, I painted all of the cavities with conducting paint and used the plastic finger guard, to which the neck pickup is mounted, with a foil shield pasted on the underside, in direct contact with a considerable area of the conducting paint. I was unsure, even though I thought it likely, whether this was what they meant by a shielding plate, so I did ground the tone pot to the volume pot. Is there potential that that is why I am getting no sound, or is that just a redundancy that shouldn't cause an adverse effect? I think I have a half a memory that too many ground connections can cause trouble, and that would certainly be an easy thing to fix if it is the likely cause. If that does not seem a likely explanation, though, how on earth do I sort this out, when everything looked just as it was supposed to be?

Rob

[eschertron]

"no sound" can result from a simple wiring mistake at any number of points in the wiring harness. With all the wiring new, then all the wiring becomes suspect. A lot of ground to cover.
If you can, post pictures that show the entire cavity, and annotate which wires/colors go to which pickups. Four-way switch? Please post what it's supposed to do and how it is supposed to wired up. Maybe help can come that way.

If there is a ground connection missing, that could kill the sound. But again, lots of choices. If the grounds are not optimal (but present), you'll get a little extra noise in your signal.

Just thinking out loud. No sound? No crackling when the pots are turned? No hiss, no hum? Start with the jack wiring.

[RobRed]

"no sound" can result from a simple wiring mistake at any number of points in the wiring harness. With all the wiring new, then all the wiring becomes suspect. A lot of ground to cover.
If you can, post pictures that show the entire cavity, and annotate which wires/colors go to which pickups. Four-way switch? Please post what it's supposed to do and how it is supposed to wired up. Maybe help can come that way.

If there is a ground connection missing, that could kill the sound. But again, lots of choices. If the grounds are not optimal (but present), you'll get a little extra noise in your signal.

Just thinking out loud. No sound? No crackling when the pots are turned? No hiss, no hum? Start with the jack wiring.

Thanks for your prompt reply. Boy, did this get me thinking about a lot of stuff. It is really too much for me to include in detail in this context, so I will try to keep somewhat brief and focused.

I will follow your last recommendation, to start with the output jack. In fact, just before I went to bed last night, I looked that topic up online and came to find that one of the resources I had used mislabeled which terminal was which, so I went to bed hoping all I would have to do is pull out the outlet and switch the wires. Unfortunately, I found another discussion this morning that said, if the lead and ground are switched on the output, you should still get sound, but it will just be muddy, noisy, and ugly. For now, I am going to hope that individual was mistaken, because to have to sort this out otherwise will represent a huge inconvenient mess.

Part of the problem is that all the wiring is done on the back of the pick guard. There is a cavity for the wiring to fit into, but you can't view it in the cavity. It's just a narrow hole in the front of the body of the guitar for the wiring to fit into. If switching lead and ground on the jack doesn't fix the problem, it will be a mess. I will have to remove the strings and then remove the neck pup from the pick guard, before I can flip it over to assess the problem. Then to test whatever I think might have fixed it, I will have to remount the pickup, then the pick guard, and finally the strings. That is absurd. In fact, if it is not the jack, I can only wonder if damage was done to my correctly done wiring by having to jam it down into the narrow cavity sight unseen. In the end, I've come to the conclusion, that if rewiring the jack doesn't fix the problem, I am going to open the body up from the back to enlarge the wiring cavity and allow testing and examination of the contents without having to take the guitar apart like that. It will be a job, but it will be far less of a nuisance than trying to figure it out as it is. I would then just have to enlarge the cavity, open it up to the back of the guitar, paint the newly exposed surfaces with electrical paint, and create a cover plate for the new opening in the back of the instrument. That would allow me to test my work until it was functional in a sane manner.

Thanks, again. Rob

[Mick Bailey]

There's an old technique called the 'disruption test'. Basically. plug the guitar in and use an uninsulated metal probe to check through the main connection points in your guitar. Begin with the hot terminal of the output socket. Loud buzz? move to where that connects. Then back from there through pots and switches. Turn your pots right up. Everywhere you would expect to get a signal, you should hear a buzz through your amp when you touch that point.

[Dave H]

I'd try a few simple measurements before cutting a hole in the back.
You can also do simple measurements to check the control plate wiring before final assembly.

Do you have a digital multimeter? A cheap one will be good enough.
Connect a cord to the guitar and check for continuity (< 1 ohm) between the sleeve of the jack and the guitar's bridge and control plate. Then connect the meter between the jack tip and sleeve, turn the vol pot fully CW and measure the resistance in each position of the PU switch. For a stock Tele it should measure something like 6k in the bridge and neck positions and 3k in the middle position (I'm not sure what your fourth position does). Now turn the vol to zero and it should measure low resistance (< a few ohms) for all PU selections.

[big_teee]

Like Dave H said.
I start with a guitar cord plugged into jack and start checking ohms continuity from the jack to pots and switch, with a multimeter.
Like said, some pictures will help on advice on how to proceed.
GL,
T

[RobRed]

I'd try a few simple measurements before cutting a hole in the back.
You can also do simple measurements to check the control plate wiring before final assembly.

Do you have a digital multimeter? A cheap one will be good enough.
Connect a cord to the guitar and check for continuity (< 1 ohm) between the sleeve of the jack and the guitar's bridge and control plate. Then connect the meter between the jack tip and sleeve, turn the vol pot fully CW and measure the resistance in each position of the PU switch. For a stock Tele it should measure something like 6k in the bridge and neck positions and 3k in the middle position (I'm not sure what your fourth position does). Now turn the vol to zero and it should measure low resistance (< a few ohms) for all PU selections.

I thank all who have responded but am responding to you because you didn't like my idea of cutting into the back of the guitar. I'll put it this way. I am very confident of my soldering and followed the schematic flawlessly. I have done ridiculously more complex projects than this and had no problem whatsoever, and I checked everything carefully before I put this guitar together. The main problem as I assembled it was that it required a somewhat uncomfortable push to make the wiring fit in the existing cavity, and I must wonder if, with the four-way switch that came with the wiring kit I got, it is just a bit too large to fit in the existing cavity with the wiring, and pushing it into place either pulled a connection loose or resulted in a ground to the conductive paint I coated the cavity with at a point in the wiring where a ground connection is, let's say, inconvenient.

This is not a collectible instrument that I will be diminishing the value of by cutting into it. It is a knock-off hollow-bodied Tele by a brand that turned out to be much junkier than the reviews suggested (which is exactly why I rewired the thing in the first place). It will be a bit of a nuisance to do the work, but I am a woodworker, and I have done similar work on guitars before. One of my complex projects was to take an Ibanez solid-body that I found cheap at a flea market, put some much better pickups on it, insulate the cavities, and rewire it to have four pots and 6 mini switches. The fourth pot is a tone control I built that uses a rotary selector switch to choose among 6 capacitors. It's huge. The mini switches allow me to select among the two single coils in neck and mid positions and either pole of the bridge humbucker and then have them running in parallel or series and in and out of phase. You have to know I was compelled to enlarge the wiring cavity dramatically to fit all that stuff in there, but it worked fine. I got a sheet of cover plate material and made plates for front and back that look like they could have been original to the instrument. And again, as complicated as that project was, it works fine. I am very careful with electronic work.

I have a good quality multi-meter by Fluke, but the problem is, I already know without question that something is not right, and the only way I can really determine what it is is to disassemble the instrument. That is not a small or insignificant trick. It means removing a perfectly good, brand new set of strings that will not go back on this guitar and may be wasted (with the bend in the end of the strings from having been wound on the tuners, they get caught up on the back of the pick guard coming through the instrument and will not push through). It means the nuisance of disconnecting the neck pup from the pick guard. Neither of those is a life altering event, but the potential of having to do them repeatedly turns me off.
Then I could determine what got fouled up when I forced the electronics into the tiny, narrow cavity, and fix whatever it is, and just mess it up again and potentially go through the whole thing repeatedly, by having something fouled up when I again try to make things fit where they really don't quite fit.

If I open up the cavity from the back, it will offer two major benefits that will put this to rest. First, it will make it so things fit better and I don't have to worry about damaging the wiring or creating a short by trying to make it fit together. It will be deeper, so the switch should not come close to reaching the back of the cavity, and I can make it wider, too, to leave more room for the wires. Second, if in spite of that I put it together and still have a problem, I'll be able to do exhaustive analysis and find and potentially repair the problem without taking the instrument apart yet again. It is a junk guitar that I hope to make work better than it was designed to work, and it won't bother me at all to have access to the electronics through the back of the instrument, even though it was not an intended part of the design. It's not the dire error I would make if I cut open the back of a true Tele.

Thanks, again. Rob

[RobRed]

Thanks, Mick. That is the basis of the whole problem, as I have outlined it in my detailed response to Dave H. I can't test anything on this other than the pups, the bridge block, and the output jack, unless I disassemble the guitar, and that was the basis for my putting the question up. Basically, I couldn't figure out how to assess the problem and reassemble the guitar without potentially recreating the damage and having to go through the whole thing all over again, and I just didn't want to go through that. I have decided, since this is a nothing special knock-off guitar, to open the wiring cavity right through to the back of the instrument and enlarge it. Then there will be less likelihood of damage on reassembling it once I've corrected the wiring, and if there is a problem, I may be able to deal with it without taking the guitar apart yet again, just by working through the open back of the cavity. Thanks for your suggestion. I will apply that when I do disassemble the guitar and try to figure out what went wrong. Rob

[RobRed]

Thanks, Terry. I will apply your recommendation when I get to that point. I don't think putting pictures up will help. The schematics are straightforward and certainly not part of the problem, and the wiring is tight enough that it would be really hard to tell looking at the photos I took what's what or to hope to find a problem from looking at the photos. Thanks, again. Rob

[Leo_Gnardo]

responding to you because you didn't like my idea of cutting into the back of the guitar.

Of course, it's your guitar and who cares if you turn it into swiss cheese. BUT, plenty of other folks (including me) have wired up teles of all sorts, put in and taken out 4 way switches, added middle pickups, then 5-way switches, added extra controls, turned the whole control plate backwards, piezo bridges, all sorts of things, but never had to carve a hole in the back of the instrument. Without going on for 4 long paragraphs, you CAN solve your problem without doing that. AND, even if you do add a rear access plate, I doubt it's going to make the solution to your problem any easier.

I'll leave finding the solution to you and those other MEFsters who have been brave enough to answer so far.

What does intrigue us, is who made the dam' thing, so we and others can avoid them. Naming the half ass builder would be a public service we all could appreciate.

I wish you the best of luck. And don't forget, making mistakes is the way we learn. I'm no better than anyone else - I've made plenty. When you get your Tele working the way you want, you will have learned something, that's for sure.

Over 'n out.

[RobRed]

Hello, Leo:

As I tried to explain in a response to another helpful soul, I think the problem may be that in this make-believe tele, the cavity is not quite large enough for the wiring and the four-way switch to fit comfortably, as the switch is bigger and bulkier than the original, and the cavity is markedly narrow and shallow. I don't think allowing the wiring more space and giving myself direct access to avoid this becoming an ongoing, repetitive nuisance can legitimately be compared to making Swiss cheese, although I recognize you meant that humorously. This thing is more of a nuisance to me than I want to know about, though, so I am going to do what strikes me as giving the greatest likelihood of putting it to rest promptly. It was not a complicated wiring problem, I have done much more complicated wiring without issue (I've never had a problem with wiring a guitar and in response to another soul, I described one absurd guitar project I did that had all sorts of room for errors, and it came out just fine), and I was confident with good reason that I had wired it up appropriately. I really think I'm going to find either that on my having to force the wiring and the four-way switch into a cavity too small for it (remember, this is not a Fender--the cavity is tiny), that either something got torn loose or it got pushed up against something it should not be in contact with. It's as simple as that. I am not looking for a tremendous learning experience here. I won't go into detail, but my life is very complex and distracted, and I just don't have the time to make this a long-term learning endeavor. It's three years since I bought the thing, I bought the pups not long after that, and it took me this long to even be able to think about trying to fix it. I just want it to play, and I actually like the idea of having a cavity that can be accessed without taking the guitar apart. I'm not trying to prove anything to anybody, I'm not going to be showing it off to anyone (it's unlikely another soul will ever see the back of it), and it is nothing I would ever hope to sell to anyone, never mind a person who might be critical that I had put a cover plate where it didn't belong.

The brand is Xaviere. It got all these tremendous reviews. I always liked playing blues on hollow-bodied Teles in shops, but I own 22 other guitars already, and I just couldn't afford the Fender, so I thought if this was as great as they described it, for the cost it went for (which I no longer recall), it would be great. Well, the guitar had the worst hum I've ever heard (it allowed for no appreciation of musical sound at all), which is what led me to rewire it. On top of that, the frets were a joke. They hadn't been dressed at all and stuck out sharp on either side of the fretboard. That is how I came to the conclusion that the bulk of the reviews must have come from the manufacturer and friends or family members thereof, but maybe I just got a clinker. Thanks for your input. Rob

[Leo_Gnardo]

I really think I'm going to find either that on my having to force the wiring and the four-way switch into a cavity too small for it (remember, this is not a Fender--the cavity is tiny), that either something got torn loose or it got pushed up against something it should not be in contact with. It's as simple as that.

Well I had that thought too. I doesn't solve the hum/buzz but sure, if circuit points carrying signal are crammed up against conductive paint sure you can expect the signal to be diminished or missing. How about routing the control cavity to standard size at least, or a little bit larger if you can. Even "back-routing" to create extra space below decks but still have enough wood on the surface so you can mount the control plate and not have any telltale gap into which picks, dimes, set lists, love notes, crumbs & other objects can fall.

I'm glad you're taking this project with a sense of humor. You need that to see your way thru an otherwise miserable experience. Hope you wind up with a terrific guitar after all is said & done.

[Dave H]

I have a good quality multi-meter by Fluke, but the problem is, I already know without question that something is not right, and the only way I can really determine what it is is to disassemble the instrument. That is not a small or insignificant trick. It means removing a perfectly good, brand new set of strings that will not go back on this guitar and may be wasted (with the bend in the end of the strings from having been wound on the tuners, they get caught up on the back of the pick guard coming through the instrument and will not push through). It means the nuisance of disconnecting the neck pup from the pick guard. Neither of those is a life altering event, but the potential of having to do them repeatedly turns me off.

There's no need to completely remove the strings, just slacken them off, pull the end out of the hole, pull the loose wraps off the peg, tape them together then fold them back out of the way. They can be refitted in minutes.

But it's not usually necessary to remove strings on a Tele. With the control plate out most faults can be found by inspection/DMM. If you are worried about shorts to the conductive paint check it's working OK before and after refitting the control plate.

We all make mistakes and as our good friend Enzo likes to remind us -

“Never look for an excuse not to check something”

Good luck.

[big_teee]

Thanks, Terry. I will apphly your recommendation when I get to that point. I don't think putting pictures up will help. The schematics are straightforward and certainly not part of the problem, and the wiring is tight enough that it would be really hard to tell looking at the photos I took what's what or to hope to find a problem from looking at the photos. Thanks, again. Rob

The pictures were for us, so we could see what you have, and what your working on.
Pictures also cut down on the amount of questions we ask you to know what you're doing.
GL,
T

[nevetslab]

Tackling the re-wiring of your hollow body Tele look-alike

Thanks, Terry. I will apply your recommendation when I get to that point. I don't think putting pictures up will help. The schematics are straightforward and certainly not part of the problem, and the wiring is tight enough that it would be really hard to tell looking at the photos I took what's what or to hope to find a problem from looking at the photos. Thanks, again. Rob

It's often the simplest circuits that those of us who are involved in very complex amplifier circuits and such make the most mistakes. And, when the build is so space-constrained as yours sounds, I feel your frustration.

A couple years ago, I came back to a bass guitar project I had first tackled back in 1968...modifying a stock Gretsch 6070 Tennessian Hollow Body bass, adding a Gibson Humbucker as a neck pickup. I had disconnected the stock Gretsch pickup, but this time around, decided to rewire the instrument from scratch. Now, the back of the Gretsch has a huge opening underneath the body pad and plastic cover, though where I was going to place the controls would still be a major fitting problem with my large adult hands.

So, after deciding upon the mechanical orientation of the two volume knobs, two tone knobs and selector switch, along with the mute switch and output jack, I cut a piece of cardboard and transferred the mounting centers from the body to this, and mounted the pots, switches and jack to it to wire up.

With where you are on your project, and not knowing where you've made the mistake(s), I'd suggest pulling the wiring back out and starting over in a similar fashion, so you can verify everything IS wired correctly first, then do the tedious fitting operation.



I had then wired the two pickups, using fresh cable from what had been installed before, and connected the two cables (single conductor shielded) to the two volume controls while the wiring was still on the cardboard form, so I could verify the wiring before the tedious operation of fishing in the controls & switches without breaking anything. I did have to revise the tone control wiring, having wired the controls backwards the first time.

It was a tedious operation, but, the end result, having first verified everything was wired correctly, there weren't any surprises once assembled.