Wiring mistake? Input sound when lead inserted but no output

[dajaphonics]

I exchanged my mudbucker in the neck position for a Gibson style bridge pickup installed in the neck position in a Epiphone ET-280.

 

Here's a photo of the way the working mudbucker was installed before I disconnected it.

 

 

I screwed down the bridge pickup and wound the e string to see if it still works. There is some sound coming out of the output when I insert up to the first ring of the lead but can't get the pickups to output. (FYI before the installation the bridge pickup worked perfectly fine). I tried playing with the switches/volume/tone and still nothing. There was a little bass sound coming out when I first wiggled around the jack but I haven't got any sound out of it since.

 

I haven't screwed down the new pickup yet since I'm still working out where it should be placed exactly and there's no screw holes where it will fit. I'm assuming this pickup won't work yet because it's not grounded, but from what I understand the other pickup should still work as it was before.

 

I'm just going tot include as many angles of the soldering job I did so you can possibly see what's potentially wrong. Is there anything obviously wrong or a place I can troubleshoot my connections?

 

 

 

 

[Woodinblack]

The only thing I can see is that maybe the centre of that switch has become shorted to one of the wires where the insulation is gone - certainly could be by the last photos, but that wouldn't produce the symptoms you are saying.

Considering the sound with the jack etc, is it possible that while you are looking at the switch and making assumptions that as that is the only thing you changed, that must be the fault (which is reasonable), maybe by taking it apart, the wire in the jack socket became disconnected or something, or some other issue further down was caused?

 

Actually looking at the last photo, did you solder the earth of the pickups to the earth of that cable going through, as if you did it might have melted the insulation inside the metal shield, which would produce the same results.

[dajaphonics]

Thank you for looking at this @Woodinblack

 

I'll check out the wiring in the jack socket. I soldered the earth of the pickup to that metal cable going through. That's where the previous pickup was soldered so I thought that would be fine (I didn't do the previous job).

 

 

[Woodinblack]

With what I can see I would say that almost certainly the jack socket hot is shorted to the sheild, and that is more likely to be your problem.

[dajaphonics]

Is this what you're referring to @Woodinblack ?

If so, I also didn't do this soldering job and didn't change it recently.

 

 

 

 

 

Edited May 3, 2022 by dajaphonics

[dajaphonics]

[Woodinblack]

1 hour ago, dajaphonics said:

Is this what you're referring to @Woodinblack ?

If so, I also didn't do this soldering job and didn't change it recently.

 

 

Yes, that is what I was refering to - it looks shorted. That black wire has been overheated quite a bit (why the insulation is breaking down) and could touch the metal shield.

I don't mean the blue wire, that is the earth wire connected to the shield.

I know you didn't do it, but you took the bass apart and it looks like an accident waiting to happen, so actually just moving it may have been enough.

Obviously you can never fully tell with a picture, but it is worth redoing if you can.

 

I am guessing you haven't got a meter or anything?

 

 

[dajaphonics]

38 minutes ago, Woodinblack said:

I am guessing you haven't got a meter or anything?

 

I actually just got a meter. I get it, I did a similar thing with a synth not that long ago where the output jack got disconnected. I guess those things are generally pretty fragile.

[Woodinblack]

6 minutes ago, dajaphonics said:

 

I actually just got a meter. I get it, I did a similar thing with a synth not that long ago where the output jack got disconnected. I guess those things are generally pretty fragile.

 

No, they are generally fairly robust, but that wiring has been made fragile.

 

So yes, stick a jack in the socket and buzz out across the sleve and tip of the other end, with the volume full up (and I am not sure what sort of wiring it has) there should be a non zero resistance (ie, more than a few k) between the two.

If there is a short between the two, remove the black wire where the tone connects the output jack and run another wire between the two.

[dajaphonics]

4 hours ago, Woodinblack said:

 

No, they are generally fairly robust, but that wiring has been made fragile.

 

So yes, stick a jack in the socket and buzz out across the sleve and tip of the other end, with the volume full up (and I am not sure what sort of wiring it has) there should be a non zero resistance (ie, more than a few k) between the two.

If there is a short between the two, remove the black wire where the tone connects the output jack and run another wire between the two.

 Ok, so I got the multimeter. Lead into the jack. I put the multimeter on the other end. I understand buzz out means use the "sound wave" setting so it beeps? If so I did that and put the multimeter on the other end of the cable. It beeped reptitively.

 

Next, I set my multimeter to 2000 ohms and got a read of zero when putting the multimeter on the side of the cable not connected to the jack. Hope this is right. If so, then I guess just replace the wire you mentioned?

 

Also, I put the end of the cable up to each of the pickups with it plugged in and got some noise out of them so that tells me the pickups are installed correctly I believe. Now that I think of it I remember playing the bass and sometimes getting a spotty connection from the output jack at times. I'd have to wiggle the cable sometimes to get a decent connection.

 

If so I'll go off and look to see where I can find a cable.

 

Edited May 3, 2022 by dajaphonics

[dajaphonics]

I went to Home Depot (US) and found some wire. I realized I don't have anything to desolder but tried to do this anyways.

 

 

So did I mess this one up? I was thinking the hot and the ground may be soldered together. Oh boy. If I have to redo it, where should I solder the white cable?

 

I also noticed another crack in the casing of the cable going to the middle terminal. Do you think I should redo this wire as well?

 

[Woodinblack]

9 hours ago, dajaphonics said:

I went to Home Depot (US) and found some wire. I realized I don't have anything to desolder but tried to do this anyways.

 

 

So did I mess this one up? I was thinking the hot and the ground may be soldered together. Oh boy. If I have to redo it, where should I solder the white cable?

 

I also noticed another crack in the casing of the cable going to the middle terminal. Do you think I should redo this wire as well?

 

I wouldn't worry about the middle cable at the moment, time to get the jack sorted.

 

In the words of the song, time to rip it up and start again!

 

Looking at the socket from that orientation, you want one wire going from the shield of the wire to the ground of the plug. I suspect you already have that, but you should check that it buzzes from the outside of the plugged in lead to the body of one of the pots.

The other lead, the white one, remove it from where it is, and it needs to go to the same wire that connects the left of the green capacitor on your tone to the volume. But the thing that may be an issue is that that blob of wires on the tone might already be shorting the output. Again, measure it with the meter. Measure between the two outside terminals of the tone. If they are shorted out (ie, it reads 0), turn the volume the other way and try again.  If it still reads 0 then the cable is shorted somewhere in that sheild soldering.

 

 

[goingdownslow]

Do folk still solder using one of these...

[dajaphonics]

So I buzzed the pots with the cable plugged in. Multimeter beeped. Just seeing if this is what you meant.

 

So before I change the white wire I wanted to confirm where I should solder it.

 

Should it go on the back of this terminal where my screwdriver is pointing?

 

 

I also noticed this wire looks like it had something connected to it at one point in the photo below.

 

 

Edited May 4, 2022 by dajaphonics

[Dad3353]

For my money, I'd recommend removing everything, cleaning up the component tags, and re-wiring from scratch with decent wire/cable. There's not much to be saved, there. If necessary, draw a circuit diagram of how it should be wired up before removing it all. That exposed 'shielding' is doing nothing worthwhile in that state, and reliability would be greatly enhanced by entire replacement. Once cleaned up and correctly soldered, it will all work as it should, for many years/decades to come.
Just my tuppence-worth. 

[dajaphonics]

22 minutes ago, Dad3353 said:

For my money, I'd recommend removing everything, cleaning up the component tags, and re-wiring from scratch with decent wire/cable. There's not much to be saved, there. If necessary, draw a circuit diagram of how it should be wired up before removing it all. That exposed 'shielding' is doing nothing worthwhile in that state, and reliability would be greatly enhanced by entire replacement. Once cleaned up and correctly soldered, it will all work as it should, for many years/decades to come.
Just my tuppence-worth. 

Thanks for the input. Perhaps but I'm struggling with this bit. Will there be sound quality differences with new cabling compared to the original? 

 

Also any advice for desoldering? Should I get a sucker pump? I see some people use flux. Would I be able to get away with just using flux and some exposed speaker wire to extract the solder?

 

Thanks 

[Dad3353]

1 minute ago, dajaphonics said:

Thanks for the input. Perhaps but I'm struggling with this bit. Will there be sound quality differences with new cabling compared to the original? 

 

Also any advice for desoldering? Should I get a sucker pump? I see some people use flux. Would I be able to get away with just using flux and some exposed speaker wire to extract the solder?

 

Thanks 

 

Any sound quality available after re-wiring will be there for years/decades to come. The present bird's nest can fail at any time, with the chances stacked against it failing when it doesn't matter much. Whilst the bass is open, and it's all there in front of you, it's the ideal time to do a Good Job, once, then close up the bass and play with confidence. That, in my opinion, is well worth it, even if, for the short time the current stuff works, they sound the same.
There are basically two main systems for de-soldering, and neither are expensive; if one is to do any more work of the sort, both are a very reasonable investment. A solder sucker costs little (type 'solder sucker' into Amazon; there are whole kits for about a tenner or so...). De-soldering braid is very handy; I would use both, depending on the job in hand.
Flux is a different matter. Good electronic-use solder is flux-cored, so the flux is applied at the same time as the soldering, so additional flux is rarely needed. It may be useful when soldering big (a relative term...) metal surfaces, such as pots, but, in general, cleanliness of the surface and a suitably-powerful iron are what's needed. Plumbers use flux to keep the soldered area clean when using a blow-torch, but it's not essential for the type of soldering we do on amps and instruments. I use it when soldering piano-wire undercarriages for my model RC 'planes, but never for electronics.
For basic soldering, a small (a relative term...) 30w iron does a Good Job, but a more powerful iron has more uses (soldering on pots, for instance...). I've used Weller irons for decades; a Weller 100w iron will see you out, and do all you're likely to want. An important point, whatever the iron, is to have a damp sponge close by, to wipe the tip frequently, removing excess solder and residues. Having a clean tip, at the right temperature, using the tip to heat the wire, then applying the solder, which should just flow, is the key. I would go out on a limb, despite my interest in ecology matters, and recommend the use of 60/40 solder, and not the 'lead-free' stuff (which works, but requires some experience to use, and is not suitable for amateur use, in my view...).
There, I hope that's enough. Come back with more questions if doubts subsist. 

[Woodinblack]

I would do a variation on what Dad is saying for someone not that comfortable with soldering.

That huge earth braided cable is the main issue, but it is soldered and absolutely certainly working as an earth. Currently too well.

 

I would leave that cable as the earth and cut off the black wire that goes through it, on the volume, tone, switch and socket - It is probably shorted everywhere anyway, and it would be harder to unsolder.

So the sheild would touch the outside of the switch, the body of the volume and tone, and a soldered connection which is your blue wire.

 

Then run one wire from the center of the switch to the volume, and the tone, and the output to the centre of the socket.

 

I can't really see how the volume is wired under that wiring, so I can't say what pin it goes to.

[Woodinblack]

1 hour ago, dajaphonics said:

So I buzzed the pots with the cable plugged in. Multimeter beeped. Just seeing if this is what you meant

.

 

 

From the body of the volume (or the tone if you want), to the other end of the jack socket, ie, the bit that you can't see in your photo that you would plug into the amp.

[dajaphonics]

9 minutes ago, Woodinblack said:

 

From the body of the volume (or the tone if you want), to the other end of the jack socket, ie, the bit that you can't see in your photo that you would plug into the amp.

 

Ok I did this and it buzzed.

 

 

Additionally you may be right, I need to replace some of this cabling. The black casing part of this top wire here just started crumbling when I started pulling away the shielding.

 

 

 

 

[dajaphonics]

So I replaced the white cable which is now the green cable. It's routed to the tone pot. Still no volume out of the bass. It looks like the soldering iron touched the it a little. I think I can just put some electrical tape on it. 

 

I was able to lift some solder off so I guess I'm slowly improving my skills with this project. I however dropped a dollop of solder on the back of the pickguard. whoops 🤭

 

 

[dajaphonics]

So I'm trying to understand the wiring. Does anyone know a good site or a diagram of the wiring schematic for this? I guess it would be considered a Master Volume-Master Tone-3 Way Switch setup. I saw a German site but didn't see the Epiphone ET-280 on there: 

 

http://www.ak-line.com/medium/Bassschaltungen.pdf

 

 

[dajaphonics]

On 04/05/2022 at 09:52, Dad3353 said:

For my money, I'd recommend removing everything, cleaning up the component tags, and re-wiring from scratch with decent wire/cable. There's not much to be saved, there. If necessary, draw a circuit diagram of how it should be wired up before removing it all. That exposed 'shielding' is doing nothing worthwhile in that state, and reliability would be greatly enhanced by entire replacement. Once cleaned up and correctly soldered, it will all work as it should, for many years/decades to come.
Just my tuppence-worth. 

 I took your advice. I ripped it all out and started again. I watched a step by step video but he didn't show how to do the switch. It looks like the middle terminal is grounded.is that right? It looked like both black wires of the pickups were connected to this previously. 

 

Here's some photos of progress.

 

 

[Woodinblack]

Assuming you just haven't connected the wire to the volume from the centre switch yet, as you haven't got round to it, looks like it should work. I can't tell because of the angle but there is a link between the tone control outside tag with the capacitor and the case is there?

[dajaphonics]

5 hours ago, Woodinblack said:

Assuming you just haven't connected the wire to the volume from the centre switch yet, as you haven't got round to it, looks like it should work. I can't tell because of the angle but there is a link between the tone control outside tag with the capacitor and the case is there?

Here is a closeup of the tone control. I don't think so.

 

 

I hooked up the middle terminal of the switch to the outside (left) which I believe is the input terminal of the volume. I plugged it in and get no sound at all. 

 

Here's what it looks like. 

 

 

Additionally the switch now won't stay on one side but will on the other. It keeps popping back to the middle position.