SF IV no bridge pickup sound

JohnW63

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That took some tiny mirror effort. The switch has lots of " stuff " under the tip shaft. It looks like this:

StewMac metric switch

It's a close fit top to bottom. What I see, once I took the switch out is what appears to be white polishing compound residue and clear varnish on the top of the switch threads. Did that shoot the clear and polish with the switch in place? The solder spots look clean and shiny. No cracks I can see. The contacts look clean. With the switch out of the body, I get readings from the output jack , with tone and volume maxed 1 way = 7.5k ohm, middle = 3.87 k ohm, and the other way = 8.1k ohm That seems more reasonable. However, as my lovely assistant Mrs. W twirled the volume controls the the values jumped all over the place and very high ohms. At the ends they were stable. I also found, with a live test, the volume of each cut off way before the 0. More like at 8. Seems both my volume pots need to be cleaned properly. They look easier to remove. Now, I have to get the switch back in and in the right position.
 

JohnW63

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I've given the volume pot for the neck pickup a couple sprays with the " DeOxit Fader " spray and I still only have usable volume from position 9 to 10. That seems almost pointless. It's the same with both pots. If I were to graph the resistance of the volume pots is would start at around 7K and then quickly jump to 120K and then as you dial it out, it moves down through 100s, the 90s , then 80s,,, etcetra until 20k then jumps all the way down to something near 4 ohms.
 

JohnW63

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Oddly, after putting things back together and putting the guitar on the high gain jack on the amp, the volume works much like expected. It still drops to nothing, at about 1, but I can live with that. Next issue. I would like to clean the bridge pickup volume pot. The knob won't life off the pot shaft. The other three do. I certainly don't want to pry with a tool against the top.
 

JohnW63

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I got it off. Saw a video that recommended pulling with a shoe lace. I used a cloth wrapped all the way around the bottom of the knob and got it moving.
 

BradHK

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Great updates! What was preventing the selector switch from being removed?
 

GAD

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I got it off. Saw a video that recommended pulling with a shoe lace. I used a cloth wrapped all the way around the bottom of the knob and got it moving.
Nice! Shoe-lace was my go-to until I bought one of these. Total must-have if you work on guitars:


Screen Shot 2022-09-19 at 1.36.01 PM.png
 

JohnW63

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Brad,

I think peering at it with a mirror at a funk angle and a flashlight allowed me to see there was nothing in the way, but it was a tight fit. So I angled it and then gave a little tug on the wires headed toward it and it came out. It went back in easier. The only change I made was wrapping the ground wire around it and not let it go under it. Maybe the thickness of the ground wire is what made it tight.
 
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