This slick Japanese-built Fender Jazzmaster is a fine representative of Fender’s offset-waist solid body designs.
The volume potentiometer for the bridge pickup was open-circuit over part of its range. The set screws under the bridge were coming loose and the string height would get crazy-low over time. This guitar also broke high E strings for no apparent reason. Let’s go to work!
The control on the right, the volume control, has been replaced before. This is an inexpensive potentiometer, often sold under different hobbyist brand names. We will continue to disassemble the guitar to look at a couple of other issues.
Years of sweat have gifted us with a bit of rust and staining of the beautiful white finish. Fortunately, most of this is out of sight!
But I do want to clean up what I can, if for no other reason than to get everything back flat again. This abrasive stick is making a tiny dent in the rust.
The heavy artillery is brought to bear to get off the really hard-to-clean stuff. Wish me luck!
The various bits of hardware were polished and waxed. This is pretty solid now. Nothing seemed out of the ordinary that would account for strings breaking. Maybe the problem will show up during setup.
The neck angle is good on this guitar. But, off the neck comes, if for no other reason than to clean up this hardware and to focus on the fretboard and fret cleanup away from the pickups.
The frets are getting a quick dressing and polish. The fingerboard was dry and soaked up several applications of Dr. Duck’s Axe Wax. I love that stuff!
This is exactly the shim used by the last person who put this guitar back together. I matched this shim thickness with a leaf of steel from an inexpensive set of feeler gauges from the car parts store. Also, can you spot the ‘country of origin’ decal on this guitar?
All the hardware on the lower half of the pick-guard was unbolted, and the pick guard was set to the other side. The neck pickup controls on a Jazzmaster are small potentiometers set up on a roller-like knob scheme. Those are 100% and were returned to service as-is.
The new control is an Allen-Bradley sealed military control. As a rule, service people prefer unsealed controls, because they can be cleaned and lubricated. However, in this case, I decided to go with a sealed, stainless-steel unit, because of the sweat and grime that this guitar has seen over time.
As the body of the Allen-Bradley control is stainless steel, it is nearly impossible to get a good solder joint using conventional solder and heat sources used for common electronics. In this instance, an extra toothed lock washer and a ring lug will make the positive connection between the metal body of the control and the ground buss of the guitar.
Here, I’m magnetically coupling the output signal from an audio signal generator to the bridge pickup to check the proper operation of the new volume control. The output from the guitar is jacked straight into my new Marshall Stack visible in the background. Yep, we’re in the Big Time here!
While I’m at it, I am verifying the proper operation of the neck pickup and tone control. Look ma, no strings! It’s kinda nice to be able to check out the electronics without having to install all the pick guard screws and a set of strings.
Here is the new Mustang bridge. I will put a coating of Teflon tape on the set screws, which should form a mechanical barrier to keep them from vibrating loose, while not locking the screws down hard as would be the case if I were to use Loc-Tite or nail polish.
This is my trusty roll of Teflon tape, seen in the Guitar Stand blog post. Great stuff.
We don’t want Teflon on the pointed end of the set screw, nor over the hex drive end either.
Threading the screw in from the bottom will leave the Teflon tape ‘out in front’ of the screw, tightening it up enough to keep from moving up into the body of the bridge, and lowering the string height, but will be soft enough to allow adjustment, with the proper tools.
For the shorter set screws used in the saddles, I cut the Teflon tape in half and started rolling.
One down, eleven more to go! These set screws start fully flush with the bottom of the saddle rollers, so they can go in from the top.
This guy is ready to install. Allowing for time to clean up the fingerprints, this took me about an hour and a half to get to this point. Let’s string it up!
Oops. The high E string was cut right in two. Post-mortem analysis showed that there was a sharp edge on the tremolo hardware where the string ball sits. Here, I’ve disassembled the tremolo assembly again to get a better look.
Sure enough, there is a very sharp edge on the hole in the tailpiece. An appropriately-sized twist drill is just right to de-burr the sharp edge. The other string holes were fine.
I like to have a third party look at my work before the customer sees it, because another set of eyes and ears and hands may show a problem that I overlooked. Jen gives the Jazzmaster a workout and is having too much fun!
Doctor Shoen is pleased with the results! Check out doktorshoen on Soundcloud and check out his current project “The Voltage Drop” on Soundcloud, on Facebook, and in a club near you today!