Strange volume pot behaviour

Idlefrog

I just replaced the pickups, pots and capacitors in my PRS S2 single cut. I used Bare Knuckle Stormy Monday pickups with CTS 500K audio taper pots and size 22 orange drop capacitors.

Everything works as expected except for the bridge volume pot. The volume pot works in that it is at full volume at 10 and then the volume reduces as you turn the knob, but it goes to silent between 2 & 3 and then at around the 2 position you suddenly get volume again that stays consistent down to zero (not max volume).

I thought I must have damaged the pot by over heating it with the soldering iron, but when I measure the resistance between the first and middle posts the reading is 0 at position 10 and 500K at position 0 which is what it should be. I have checked the solder joints and the third post is grounded properly to the body of the pot. I have the switch hot wire going to the middle terminal and the pickup hot wire and the capacitor from the tone wired to the first post. The switch and pickup grounds are soldered to the body of the pot.

The behaviour of the bridge volume does not alter with the positions of the other pots.

Has anyone experienced this? My knowledge of electrical circuits is very basic and it is stumping me.

ICBM

Sounds like you haven't connected a ground somewhere.

Funkfingers

Remote diagnosis is usually made easier with photographs of the offending wiring. 

Here is a guide on how to add pics. http://www.thefretboard.co.uk/discussion/54241/posting-pics-vids-soundclips-how-to

Idlefrog said:

I just replaced the pickups, pots and capacitors in my PRS S2 singlecut.

If you still have the stock control parts, use them to make a visual comparison against your new installation.

Headphones

Your symptoms suggest that the wiper is not contacting the resistance track in the pot for part of its travel.

If you measure the resistance across the pot (wiper and an end) the value should change as you turn between the 500k (ish!) and zero.  I suspect as you pass the offending point the reading will go open circuit.

This could be caused by contamination, distortion of track, or a bent wiper.

Best to swap the pot.