Rewire ... Lost control of tone knob, stuck on bassy sound

axisus

i had to rewire my guitar pickups and somehow I have lost any control with the tone knob, it just stays on the most bassy tone? All wires seem ok, and I can't have frazzled it. What am I likely to have done?

strtdv

What are you rewiring? And is your pickup cavity shielded?

axisus

Paint shielding. Tele type controls but with two push pull switches.

strtdv

I had a similar issue with my SG when one of the capacitors was in contact with the copper shielding I have in the control cavity. Check no bare wire is touching the control plate, particularly if it's a tight squeeze in the control cavity

frankus

Sounds like a short is making the capacitor bleed to earth as if the wiper was all the round.

See if the capacitor is touching earth

axisus

Boy this is frustrating, the bloody thing! I have checked the pot and it is definitely working, tried a different capacitor, re-soldered joints. Nothing appears to be touching where it shouldn't be. The whole control area has been painted with shielding paint. Where the hell have I got a short???? 

Andyjr1515

Have you tried disconnecting the tone pot altogether? If so, does it sound back to normal? If so, it's definitely the pot or the capacitor or a wiring switcharound or a short. If it still sounds very bassy, then you have a different issue.

Paul_C

Try undoing the nut on the tone pot and pulling it up so that it's not touching the shielding paint and see if that sorts it out - I put a John East preamp in my first bass build and it refused to work unless I isolated it from the shielding (masking tape) so you may be suffering a similar problem.

axisus

Andyjr1515 said:

Have you tried disconnecting the tone pot altogether? If so, does it sound back to normal? If so, it's definitely the pot or the capacitor or a wiring switcharound or a short. If it still sounds very bassy, then you have a different issue.

How would one do that? Sounds like a thick question but can I just disconnect 1 wire to take it out of the circuit?

axisus

Paul_C said:

Try undoing the nut on the tone pot and pulling it up so that it's not touching the shielding paint and see if that sorts it out - I put a John East preamp in my first bass build and it refused to work unless I isolated it from the shielding (masking tape) so you may be suffering a similar problem.

I don't think that is the problem for three reasons, I have the whole tele control unit 'flipped out' of the guitar at the moment whilst trying to fix the problem

Paul_C

ok - didn't notice it was a Tele

koneguitarist

Send pic

ICBM

Is the cap between the volume pot and the tone pot, or between the tone pot and ground?

axisus

ICBM said:

Is the cap between the volume pot and the tone pot, or between the tone pot and ground?

Tone & ground. Was working fine 2 days ago!

axisus

Re soldered with my new soldering iron tip (as mentioned in other thread), and all seems to be working again. Needed a decent solder joint and wasn't getting it with my knackered old iron

ICBM

axisus said:

Re soldered with my new soldering iron tip (as mentioned in other thread), and all seems to be working again. Needed a decent solder joint and wasn't getting it with my knackered old iron

That can't be it. A bad solder joint would cause an open circuit, which would leave the tone control not working at all. You would need a short to create a stuck-fully-down tone fault.

So you've accidentally fixed what it was while you were working on what you thought it was . The bad news is that the real fault may come back later. You can guess how I know this .

axisus

Errrr .... You are right! It's gone again! Darned thing!

ICBM

First disconnect the tone control and check for sure that it is the problem - sometimes a 'tone down' sound can be caused by a partial short elsewhere.

axisus

ICBM said:

First disconnect the tone control and check for sure that it is the problem - sometimes a 'tone down' sound can be caused by a partial short elsewhere.

How does one disconnect? physically take off every wire and remove the pot or can one just remove one of the wires?

ICBM

axisus said:

How does one disconnect? physically take off every wire and remove the pot or can one just remove one of the wires?

Just disconnect the wire that runs from the volume pot to the tone pot - or the cap if thats how it's arranged. You only need to do it at one end. You don't have to remove the ground connection.

If the tone pot is not connected to the signal path and you still get the problem, it's not the tone pot.

axisus

ICBM said:

axisus said:

How does one disconnect? physically take off every wire and remove the pot or can one just remove one of the wires?

Just disconnect the wire that runs from the volume pot to the tone pot - or the cap if thats how it's arranged. You only need to do it at one end. You don't have to remove the ground connection.

If the tone pot is not connected to the signal path and you still get the problem, it's not the tone pot.

Thanks, I'll give it a try next time it cuts out - been working all day!