No Sound: New P Bass Pickup Install

[kwatx1]

Hi Friends,

Hoping for some feedback on where this has gone wrong. I switched out the pickups on my friend's Squier to some new Quarter Pound 4 string's. Was as straightforward as I expected, except now I am getting no signal.

I checked continuity at all of the ground points and got a beep at each location. When I plugged in a cable and set the multi to 20K Ohms and touched the sleeve and a string I am getting 0.03. I am not sure what value I should be looking for here.

Pics attached, would welcome any feedback on where I might be going wrong here.

I will say that I screwed up and did not test the bass out before changing the pickups, so I threw out any baseline there.

Thanks!

 

[Supernautilus]

The wiring looks right. P bass wiring is pretty simple so it should be easy to troubleshoot.

When I’m testing output at the Jack, I usually plug in a short cable and put the meter leads on the tip and sleeve. With the volume knob on full, you should get what K value the pickup is. If you get nothing, something is wrong.

The volume pot covered in solder isn’t a good sign. The lugs don’t look so healthy either. At this point, I would normally remove all the wires and test each pot separately for proper functioning. I would test the pickup separately as well, just to be sure. Then I would rewire everything from scratch.

That’s just my method though. It’s how I troubleshoot this kind of stuff. I hope that helps.

 

[kwatx1]

Thanks I do appreciate it. I did suggest my friend order some nicer new pots and would feel more confident starting from base than troubleshooting.

The volume pot lug with the pickup and tone wires was a mess and I originally cleaned it up thinking that would be my fix, but no joy.
I don’t know the K value offhand but I’m guessing google will.

The wiring looks right. P bass wiring is pretty simple so it should be easy to troubleshoot.

When I’m testing output at the Jack, I usually plug in a short cable and put the meter leads on the tip and sleeve. With the volume knob on full, you should get what K value the pickup is. If you get nothing, something is wrong.

The volume pot covered in solder isn’t a good sign. The lugs don’t look so healthy either. At this point, I would normally remove all the wires and test each pot separately for proper functioning. I would test the pickup separately as well, just to be sure. Then I would rewire everything from scratch.

That’s just my method though. It’s how I troubleshoot this kind of stuff. I hope that helps.

 

[Supernautilus]

Thanks I do appreciate it. I did suggest my friend order some nicer new pots and would feel more confident starting from base than troubleshooting.

The volume pot lug with the pickup and tone wires was a mess and I originally cleaned it up thinking that would be my fix, but no joy.
I don’t know the K value offhand but I’m guessing google will.

Yeah, a quick google search tells me the QP P bass pickup should be around 12.5K. So that's what you should see at the output jack.

As far as the pots, I would definitely recommend replacing/upgrading them. The reason I mentioned the solder was because that much heat can definitely kill a pot. I've done it myself more than once hehe.

You can pick up a pair of nice CTS for fairly cheap. A new orange drop capacitor would be good too. Test each component separately with your meter prior to installing. Then wire it up according to the SD wiring diagram and you should be all set.

 

[jeremy]

when you test the pup it self, even in circuit, but meter directly on the pups hot and ground, do you get 12k?

 

[beaubrummels]

FWIW the yellow wire going from the back of the volume pot to the jack doesn't looks like it's making a proper connection to the back of the pot. I would just reflow that and push the wire down onto the pot while it's hot and hold it, then when it cools, let go and test it again.

 

[GuitarDoc]

My guess would be that you burned up your vol pot. No need for the entire back to be covered in solder...that took a lot of heat to do that.

 

[Securb]

The wiring is correct I am with Doc I would be looking at that VOL pot first.

 

[kwatx1]

Thanks I am getting .08 checking the sleeve and tip of a cable with 20k Ohmmst full volume.
Once I turn down just a hair the number jumps to 8.68 and a nudge further hits 1.22. If I turn down to about a 6-7 the signal cuts out totally just like the vol was at 0.
Seems like the volume pots is struggling.
I ordered some CTS pots and will start fresh once they deliver.

when you test the pup it self, even in circuit, but meter directly on the pups hot and ground, do you get 12k?

 

[kwatx1]

Now I’m really confused. Got new CTS pots and rewired with a new jack and still not getting any sound.

 

[beaubrummels]

Wiring looks right to me. :dunno:

 

[Mincer]

Can you wire the pickup directly to the jack to see if you are getting sound, or at least test the pickup on a meter?

 

[GuitarDoc]

Like Mincer said, check the resistence of the pup.

Did you think that using a larger blob of solder would give you a better connection? Sometimes that is an indication of a cold solder joint. I can understand your hesitance to keep the iron on your pot as little as possible (given your past experience), but there actually IS a happy medium. The solder, in a perfect joint, should be as thin as water. If you are not able to readily get that, you need a higher wattage iron.

With 100 watt irons at less than $20 all over the place, there is no reason for not owning one that will do the job it was intended to do. A 40 watt iron is generally fine for wires and lugs but for pot backs it will do more harm than good.

Here's an example, plus you can get $2 off of that price:
https://www.amazon.com/Soldering-Ad...tt+digital+soldering+iron,aps,248&sr=8-6&th=1

And get one of these to keep the tip clean:
https://www.amazon.com/Soldering-Cl...oldering+iron+tip+cleaner,aps,182&sr=8-6&th=1

 

[kwatx1]

Thanks I have a nice solder station already. Added more in that spot as I tried reworking the wiring to trouble shoot.

 

[kwatx1]

Can you wire the pickup directly to the jack to see if you are getting sound, or at least test the pickup on a meter?

I really was not sure the best way to test just the pickups with the multi. Tried the prongs on the white and black wires direct from the pickups like in the attached pic but was just getting 1 on the display. So you are saying I can wire to a jack and then test a cable end that’s plugged into it?

 

[GuitarDoc]

Adding more solder doesn't help anything.
If you've got your multi set to 20k, then your pup is bad.

 

[kwatx1]

Adding more solder doesn't help anything.
If you've got your multi set to 20k, then your pup is bad.

When I test my Tele I get accurate (or at least believable) readings for the bridge and neck pickups as you would expect so it’s not the multi or user error.
Have a hard time believing the actual pickups are bad, seems way more likely I’ve botched something up though.

 

[ErikH]

If you put the DMM leads on the hot and ground of the pickup, with it set to 20K, and it reads nothing, the pickup is bad. Do the same with the pickup you pulled for verification.

 

[jeremy]

you can also test the two coils directly on the solder points if the whole thing doesnt give you a reading. id guess one coil might be bad

 

[GuitarDoc]

When I test my Tele I get accurate (or at least believable) readings for the bridge and neck pickups as you would expect so it’s not the multi or user error.
Have a hard time believing the actual pickups are bad, seems way more likely I’ve botched something up though.

Exactly my point.
If you tested your pup with a multi set at 20k and you get a reading on .08, then believe it or not (your choice) but the pup is bad. By "pup is bad" I mean that there is something wrong at some point between the two points where you tested it. Could be a broken lead or ground wire coming from the pup...easy fix. Could be a broken connection between the two pup bodies (a P bass, right?)...easy fix. Could be a broken coil wire...not so easy fix.