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Strange Problem with a ‘53 P-90

TM1

Well-known member
Joined
Jun 27, 2003
Messages
8,349
I have a set of P-90’s & wiring harness from a ‘53 GT that I’ve put in my R-4 (was a GT when I got it and then sent it to Kim @ Historic Makeovers about 10 years back, so seemed only fitting to be in here.
but.....
after soldering it all in the neck pickup isn’t working right.. if I tap on the poles with a screwdriver it comes through the amp, but if I strum the strings there’s nothing coming out.
I’ve been working on guitars for 47 years, but this is a weird one..
anyone have a clue? The D.C. resistance measures 8.2K ..
any suggestions?
Thanks/Cheers!
 

Mark Kane

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Jul 18, 2001
Messages
5,742
I had that happen years ago on a guitar I was helping a friend with. He had changed pickups and one culprit was soldered to a glob of solder on the pot. Polepieces popped as yours do and it measured proper continuity. I cleaned up the mess and rewired it and it worked fine. I'm sure yours isn't wired sloppily but maybe something similar to what I experienced. Just a thought.
 

TM1

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Joined
Jun 27, 2003
Messages
8,349
Mark; Thanks! I was going to pull the pickup back out and re-solder the connections. I think because of the age(67 years...) that maybe the ground connection on the pickup base is the culprit.
Thanks again!
 

marshall1987

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Joined
Jan 30, 2005
Messages
3,278
I'll give it a stab.

Does the bridge P-90 function properly? Start from there....then identify any physical and electrical differences between the working pickup and the non-working pickup. Are both pickups connected and soldered to their respective volume pots identically?

Lastly.....check for grounding and continuity issues with a digital multimeter.
 

jwalker

Les Paul Forum Sponsor
Joined
Dec 10, 2004
Messages
2,592
Make sure both magnets have the same pole towards the keeper bar. Usually south towards keeper bar for a vintage P90. Make sure the start or finish lead is not crimped under a magnet or the keeper bar. Also make the connections on the bottom are lined up with the square portion of the pickup route.
 

TM1

Well-known member
Joined
Jun 27, 2003
Messages
8,349
Thanks Jon! It turned out to be the black lead(both leads are black.. duh..) was not making a very good contact with the shield of the pickup lead. It works great now and sounds wonderful!! I steel wooled the area of the base plate that the lock washer/screw that holds the bobbin in place and re-soldered the wire
 
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