Pickup not showing DC resistance but still works?

[odibrom]

Or I can keep it and just try to fix it and use it. I can convert it into a 4 wire conductor cable instead of the braided wire.

I'd go with start from scratch and transform this pickup in a 4 wire one. You'll free the bobbins' START and END leads and that's where you should measure the coils' continuity.

Oh, can you record some clean, and crunch tones? That could give us some clues as well, because to adjective sound only goes that far...? (you're doing great, but I'm still unsure about a reverse phase or a coil not working at all)

The thing here is, the more we ask of you, the more difficult it will be to return the pickup if in fact there's a broken coil... in that situation, maybe a re-wiring to original specs on a local builder?... yeah, I know, more money thrown into it...

 

[Edika]

Truth be told I kind of gave up and asked for a return of the pickup. Not that I mind much eating the cost as I got relatively cheap but seems too much trouble for what it's worth in terms of time and effort. If I was kind of sure it was just a bad solder in one of the coils I'd be ok to perform more surgery and convert it to a 4 wire pickup. But if there's a break somewhere in one of the coils then I'm not going to get someone to rewind it as I could get a new one or one used that's working lol.
In any case I'm waiting for the sellers reply to my official request for return. I've sent him messages about it but he seems kind of deflective. I did leave positive feedback when I wired it and had signal but I realized afterwards there was an issue with it. So the guy thinks I changed my mind and suddenly want to return even though I repeatedly told there's no DC resistance and that it sounds thin and bright!

 

[odibrom]

... good luck with that...

 

[odibrom]

... and it just occurred me, could the coils be wired in parallel? It's a birighter sound than a series humbucker, kind of single coil-ish, but not quite and still feels somehow compressed like the series wiring...

 

[Edika]

... and it just occurred me, could the coils be wired in parallel? It's a birighter sound than a series humbucker, kind of single coil-ish, but not quite and still feels somehow compressed like the series wiring...

I'm not sure about the color coding of Gibson's pickups. They had one black wire as the hot and a black wire as the ground and two white wires connected together. One would think that one colour would be North and the other South as to white being North and black South. I didn't open up my other 500T to check but from what I can see there is a black wire soldered to the baseplate.
But even if it was parallel it would still give a DC resistance but quite a bit lower than expected, correct? If each coil is 7.5K it should measure 3.75K. It doesn't really sound single coilish though, just like a really bright and thin humbucker. I'm not sure honestly as I haven't listened to a parallel wired humbucker.

 

[Edika]

Checking wire diagrams it seems the north finish with the south finish are soldered together and the north start is the hot output and the south start is the ground. This is how it seems to be wired so theoretically it should work ok, if there were no issues.

 

[Edika]

One thing I should mention is that the multimeter is showing OL on the pickup if that gives any clues to the issue.

 

[odibrom]

The theory on humbuckers is that one needs reverse wound and reverse polarity coils to have a hum canceling sound. Since all coils are coiled in the same direction, what one does is to reverse it's wiring. The START and END on each coil mean the point in the wound wire where the winding STARTs and ENDs. In order to get a reverse wound coil, makers simply wire one of the coils "END first".

The general signal path for a series wired humbucker is:
- North coil START as HOT
- North coil END links to South coil END.
- South coil Start as GROUND

You can start with the south coil (which is what happens on many Ibanez wirings), keeping the same phase as previous combo and delivering the EXACT SAME TONE:
- South coil END as HOT
- South coil START links to North coil START
- North coil END as GROUND

Reversing the phase of the whole pickup won't make any difference on its tone alone, but will interfere when combining it with another. The following wirings deliver the exact same tone as previous when used alone:
- North coil END as HOT
- North coil START links to South coil START
- South coil END as GROUND

or

- South coil START as HOT
- South coil END links to North coil END
- North cols START as GROUND.

:::::::::

Another question that occurred me, can the connection between the 2 white wires not be correctly insulated / electrically protected and be in contact with the base plate or any other wire in the pickup and therefore shorting the signal path into an almost single coil-ish sound?

:::::::::

A parallel sounding humbucker has a single coil-ish tone, less punch, brighter sound (or with more high end and way less bottom end) but still retains a compressed feel to it when compared to the single coil sound. Depending on the punch of each of its coils may sound weaker if the coils are substancially different in output one one coil splits to the stronger coil.

 

[Edika]

Reading a bit more into similar issues, it seems one of the two coils must be damaged. If the winding is broken in one of the coils, it still has some connection to the rest of the windings and acts as a capacitor, so signal can pass through, albeit sounding thin and the signal not being as strong as it was. But no DC resistance will be shown when measured.

The connection between the two coils should be ok but in order to test it, I need to remove the tape between the two coils, making it more difficult to return the pickup. I could test there and se which of the two coils is the one causing the issue. The problem then lies in that either the break is close to wires connections (or them specifically if I'm lucky and just need to redo the soldering or it's somewhere in the middle of the coil which would require rewinding the coil. All of this looks like too much hassle honesty and the option of rewinding would end up costing me as much as buying it new.

In any case, since I bought it from ebay, I'm quite sure I'll be able to get my money back and return the pickup.

 

[odibrom]

... good luck then, may you recover your money back and invest it into another functional pickup.

 

[ElysianGuitars]

Reading a bit more into similar issues, it seems one of the two coils must be damaged. If the winding is broken in one of the coils, it still has some connection to the rest of the windings and acts as a capacitor, so signal can pass through, albeit sounding thin and the signal not being as strong as it was. But no DC resistance will be shown when measured.

The connection between the two coils should be ok but in order to test it, I need to remove the tape between the two coils, making it more difficult to return the pickup. I could test there and se which of the two coils is the one causing the issue. The problem then lies in that either the break is close to wires connections (or them specifically if I'm lucky and just need to redo the soldering or it's somewhere in the middle of the coil which would require rewinding the coil. All of this looks like too much hassle honesty and the option of rewinding would end up costing me as much as buying it new.

In any case, since I bought it from ebay, I'm quite sure I'll be able to get my money back and return the pickup.

That was my thought on initial reading of the thread.

 

[Edika]

Well it's off to the seller today and I'm waiting for my refund. There's another guy selling a 500T and 496R set and I might grab that instead!

Thank you everyone for you help and input!