Damaged capacitors?

[torhaa]

I'm just finished reassembling my guitar, after doing some mods... While I was soldering, I didn't become aware of the two capacitors (Orange Drop 225P - 0,0022uF) that were just under the soldering iron, but they did not touch, I'm quite positive of that. However, they got very hot nonetheless.. I measured with the multimeter between each capacitor, and they show some resistance. From what I gather, for the capacitor to be fully functional, it should measure up to infinity. I decided to put the guitar together to see what would happen, and while there was sound, it was rather abnormal... On the lead channel, the tone was very clean and weak, and it was also noise that was worse than what it normally would have been...

Is this normal behaviour for crashed capacitors...? I hope it is, as I don't know what else it could be..

[UnklMickey]

hi Torhaa,

welcome to GuitarNuts2.

torhaa said:

...From what I gather, for the capacitor to be fully functional, it should measure up to infinity....

this is true, however....

you will be reading the resistance of the tone pot, in series with, the parallel combination of the volume pot and whatever pickups are selected.

unless, of course, you disconnect at least 1 lead of the capacitor.

my guess is the caps are still okay, but you have some other wiring problem(s)

could you post a drawing or picture of the wiring you are using?


cheers,

unk

[torhaa]

Thanks!

Here are links to a couple of pics I took while I was in the guts:





I'm not good at making diagrams or something, so if these pics aren't that helpful, I can say this:

I almost religiously followed the instructions on the Quieting the Beast mod. I have three SD rail type pups, so there are five wires from each of them:
The green and bare wires have gone to the starground which is tucked in the black electrical tape between the pots and the switch. This deviates from the instructions at GN, but I am certain that the aluminium shield is connected to the switch. From the metal casing of the switch is a metal tab that I have connected to the starground, which is a metal washer..
The red and white wires are connected and tucked away in their own black little cables. The black cable from the rails go to the switch.
As for the capacitors, they are each connected to the middle ring terminal of the pots, to the starground.
On the pics, I haven't done wiring the signal cable to the jack yet, but it should be done right by now.. Also, for the ring terminal on the second tone pot connected to the hot wire from the switch, it looks as it touches the shield, but it is not.

Can't think of more to explain right now.


I'll try and measure the resistance of the caps again, tomorrow if I've got the time, thanks for the tip!

[UnklMickey]

i can't make out all that's going on with the wiring, partly because of the tape, and the way the wires weave in and out.

one thing that strikes me as odd, is the fact you are using all 3 terminals of the tone pots.

this is not normal, but i won't say it is necessarily a big problem.

[sumgai]

torhaa,

Lemme also welcome you to this here forum for GuitarNutz!

The two caps look fine. If you had truly done any damage from external heat (the soldering iron), it should show, even from the top like these photos. Most caps of this kind can stand upwards of 80 to 85° centigrade, but much more than that, they do tend to go way out of whack. Your symptoms don't describe what I'd expect from a head-damaged capacitor.

unk is right, there's entirely too much electical tape in there .... get rid of it! And while you're at it, get rid of all that lossy shielded coax cable, it's not helping your tone at all. Remember, you're already inside of a completely shielded cavity (or you should be, if you did QtB like you said.....), so this kind of wiring is redundant. Standard 20 or 22 gauge wire, solid or stranded core, will be more than sufficient here.

..............


unk, look closely at the volume pot's wiring..... do you see what I don't see?


sumgai

[UnklMickey]

no i don't see it. but dwarfed by those pix is some text that covers it............if we're talkin' about the same thing.

torhaa said:

...On the pics, I haven't done wiring the signal cable to the jack yet, but it should be done right by now.....

[sumgai]

unk,

No, I'm speaking to the 'what kind of ground connection is that?' portion of the volume pot. The center conductor of a piece of shielded wire does not inspire a lot of confidence here.


sumgai

[torhaa]

I wired most of the guts over again, paid attention to what you remarked.. However, the sound wasn't there even so.. Turned out the volume pot wasn't working anymore, luckily I had one in reserve, so.. It's up and running.
However, I have one question... I thought I should use all three ring terminals of the tone pots, but I might have misunderstood something... I removed it now, as seen in the pic below.. But what is the difference with or without..?

[sumgai]

torhaa,

However, I have one question... I thought I should use all three ring terminals of the tone pots, but I might have misunderstood something... I removed it now, as seen in the pic below.. But what is the difference with or without..?

Nothing, really. We simply don't need all three terminals in this scenario, so we don't spend the time to wire them up.

Yes, you could hook the wiper to either end terminal, and notice no difference in the pot's operation. But that does bring up the possiblity of accidentally wiring it incorrectly, or worse...... you could inadvertently create some other problem such as a solder bridge (a solder blob that undesirably shorts two contacts together). That's another good reason why we leave it alone..... no point in tempting Mr. Murphy.



sumgai

[torhaa]

Hehe, okey, thanks!