CPJM Pickup dead after adjusting pole pieces

[slartibartfast]

Hi there! My first post, so hello everybody!

Maybe someone can help me with this technical issue, my knowledge is very limited :

I wanted to adjust the pole pieces of my classic player Jazzmaster pickups (p90 style screws). Bridge no problems,
but neck pu went dead afterwards. I took it out and checked the bottom, all looks fine. What I noticed is, that
some of the bottom screws stood out, and when I screwd them back in, the screws on the top moved as well,
they are stuck to each other if that makes any sense.

Any help is much appreciated, I´ll take her to a luthier otherwise, but still think there might be an easy fix...

Thanks, Paul

[timtam]

That doesn't sound good. Did you measure the resistance with a multimeter ?

The CP's P90-like pickups are a tad odd. I don't think anyone knows exactly what the formwork is like internally, unless someone has had to rewind one ...


It could be modern molded plastic formware separating the screws from the coil wire, or more like the vintage-style wooden spacer / screw holder. The former would probably allow safe adjustment of the screws; the latter might be a little more risky.
https://www.stewmac.com/How-To/Online_R ... obbin.html

[slartibartfast]

Thanks timtam, probably stupid question: do I have to unsolder the pickup to measure it properly? Or can it stay connected, and I measure from the two solder joints on the pickup?

[Danley]

To get the most accurate measurement of pickup resistance you should de-solder; but for the purposes of just checking whether the thing works and getting a ballpark reading, just plug in a cable to the input jack, and measure DC resistance there. If no continuity, your coil probably is broken. (Make sure you select the appropriate pickup on the guitar.)

I’m having bit of trouble following what you said about the bottom screws; but to be fair I also am having trouble discerning the purpose of the bottom screws from the above pic (and odd that the bridge/neck pickups have differing construction.)

Perhaps the bottom screws secure or contain some sort of threaded bushing for the upper screws to seat? If whatever is moving has brushed up against the coils, there’s a decent chance the coil could have broken.

[slartibartfast]

Thanks Danley,

so the pickup shows max resistence, I guess its broken (bridge measures 7.5k). I`ll take it out and try to fiddle with the screws some more,
maybe it comes back to life. One thing I forgot to mention: while I touch the top screws with a screwdriver signal comes back normal sometimes.

Funny, I was just about to order a wide range hb from creamery for the neck position anyway. Only problem is, it will take quite a while before I get it...

Thank you all for your help!!!

[SpagettButler]

I'm having this exact same issue with my Squier J Mascis Jazzmaster. What did you end up finding out?