176. Is it better to have the pickup adjusted high and the pole pieces adjusted low or have the pickup low and the pole pieces adjusted high as on a humbucker? Barry Hirsh-Las Vegas, Nevada
I like having the pickup (both bobbins on a humbucker) adjusted closer to the strings as it allows more magnetic field from the string movement to cut through the coils to produce more current or output in a pickup. If the two bobbins on the humbucker are further away from the pickup and the pole pieces adjusted higher the pickup would give you less output and brighter sound. I like keeping the coils, magnetic field and strings close to make the pickup work more efficient with my playing style. The pickup is more sensitive when all components are working closer together. You can play real subtle or with lots of attack and overdrive the input stage to get more growl from the pickup. Try looking at many makes of pickups, shapes of pole pieces and type magnetic fields they have. Gretsch used a pickup they called the “Dynosonic” and was made by DeArmond Pickups company back in the 50’s and 60’s. The pickup has adjustable 1/4” diameter magnets and to get enough output out of the bridge pickup the pole pieces had to be adjusted really high. By doing this made the pickup sound slightly fuller but still not enough output to balance with the neck pickup. I like to build special shims to raise the whole pickup closer to the strings and leaving the poles adjusted lower in the pickup. I get better output and fuller sound that balances much better with the neck pickup.

177. Why are Fender bridge plates hard to drill and countersink? Robert Jones-Florence, Kentucky
During the early days of Fender they used a company called Race and Olmsted which was near the Fender plant in Fullerton, California. They used a treatment called case hardening or surface hardening of it’s steel bridge plates. The surface hardness of steels can be changed by a surface hardening treatment. This can give the surface of the steel a high resistance to wear and an inner core with adequate strength and toughness for the pressure of the bridge saddles. Leo felt the surface should be harder so the adjusting screws don’t cut into the surface and helps reduce the stress of the strings and the load required to hold the tension. Carburizing is also a term used for case or surface hardened steels. It is hard to drill and countersink holes in the bridge plates of most Fenders because of the case hardening. The case hardened steel was used on the early lap steels where the strings connect and ride over the edge of the bridge-pickup unit. The case hardened steel would keep the guitar strings from cutting into the steel. Many copy or replacement bridges made of plated brass will suffer from height screw depressions in the metal. Remember too that the steel plate in a Fender Telecaster conducts the magnetic field from the pickup and gives the Telecaster, Esquire and Broadcaster that cutting sound. The bridge cover on Albert Collins Telecaster is steel and helps radiates the magnetic field throughout the bridge and strings. He’s my favorite blues player along with Roy Buchanan.

178. What equipment do you use when doing winding seminars on the road? Jill Avery-Santa Barbara, California
There are many things I take on the road to do seminars. My helper Tim Larson assists me when doing the many shows we do each year. I will list some of the tools and equipment that I use to help repair and wind pickups on the road.
I have a homemade winder with analog counter with a 1 to 1 turn ratio. Each turn of the coil equals one turn on the counter. I have a variable speed foot control for desired winding speeds and several controls on the winder for various speeds and winding direction.
Here is a list of tools and supplies I use: I have a custom build anvil case that fits all my supplies and drawers to fit all my smaller components and hand tools.
? Hand Winder and counter mounted on a single phenolic board with foot control for various winding speeds and winding direction. I have four speeds to wind various size coils. Faster speeds for smaller coils and slower speeds for longer or heavier coils. I can wind the coils top coming or top going that allows me to properly electrically phase the winding direction of the coils.
? Directional light for winding coils. I don’t like using outside or available light. This light helps direct the light to the pickup and helps me see the shape of the coil being wound.
? Magnetizer and various mounting plates for various size magnets. I can magnetize pickups North or South or reverse the phasing or recharging old or weaker magnets.
? Various gauges of magnet wire and insulations (Formvar, Plain Enamel, Polyester etc.) I also take odd size wire and different surplus wire with odd color insulations. I take many pounds of magnet wire and I’ve noticed the insulation’s can vary from spool to spool manufactured by the same company.
? VOM meter (volt-ohm meter) for measuring continuity of coils and DC resistance. This is real important and I try to keep all my meters calibrated the same. I mainly use Fluke meters and they work best for me when on the road. I try to keep my magnet wire around 70? F. If the temperature of the magnet wire is higher the DC resistance of the coil will be higher. If the temperature is lower the DC resistance of the coil will be lower.
? Gauss meter to measure polarity of magnets and magnet strength. I have an analog meter and also a digital. I like the analog better for on the road as it is handier when you need to make quick checks of many pickups.
? Various wire cutters and wire strippers. I use several for different size hookup wire and special ones for cutting off the cloth braided vintage wire.
? Various screw drivers-slotted and phillips. I have several from small to large in both styles. I have hex wrenches and socket drivers for most jack and volume nuts. I use a variable knurl wrench for tightening the toggle nuts on Les Pauls.
? Hot wax pot with variable temperature for proper viscosity. I try to keep my wax between 160? and 170? for proper thickness and temperature.
? Inductance Bridge for measuring the Q and Henry’s in a pickup and paper for charting. I like measuring old pickups at Vintage Guitar shows and try to get as many specifications as possible on old pickups. This helps when trying to rebuild or restore a vintage pickup.
? Calipers and Micrometers for detailed measurments of pickups. I like using digital calipers that measure in both inches and milli-meters. They are pretty expensive but are an essential part of my research. I use various types of micrometers with both analog and digital reading. Agin this is important for measuring the various gauges of magnet wire and thickness of insulations.
? Soldering Iron with various tips for desired temperatures. I use a 700? F tip and rosin core solder. Don’t use acid core solders...it can eat your components. I never use a solder gun that has a large coil to heat the element or tip. They have been known to change the magnetic orientation and strength of a magnet.
? I take radius gauges for measuring angles and corners of pickups. I like measuring the various types of injection molded bobbins from Gibson and other replacement models. I use them for measuring the radius of various guitar bodies and doing this can help determine how thick the finish is on a body.
? Note pads for taking notes and measurments. I write and measure everything and especially the wiring of each instrument worked on or taken apart. You don’t know how many times that phone call will leave you wondering where that wire should go. I try to draw and measure the components. I date the volume and tone pots and measure each length of wire to insure the instrument is restored to it’s original condition. I have made wire with different color insulations and you learn how to fabricate materials for a specific purpose.
? Camera with macro lens for close-up photo’s of various angles of pickups. I keep records of old instruments and close up’s of cavitys and specific wiring. I look at them from time to time and helps give you guidelines on proper hookup and wiring. At the office I use microscopes for extreme close-ups of pickups and it’s workings. You can see all kinds of pin holes and pits in the magnet wire and magnet rods and bars. You learn lots from looking and get an idea on the manufacturing process.
? Various insulations, colors and gauges of hookup wire (cloth, teflon, PVC). When working on old or new pickups it’s important to have a supply on hand of the many gauges and insulations used from year to year. I keep the old cloth braid push-back wire on hand for restoring pickups that have been previously modified improperly and stripped of the original hardware. I don’t like seeing new wire put on old and worn pickups and it’s necessary to have the right look to keep in restored.
Supplies for restoration and special fixtures to hold pickups while working on them. I have many holding and winding fixtures that allow me to wind all shapes and forms of pickups and bobbins. I don’t like hand winding humbucking bobbins or bobbins made from plastic as they can warp and flair if wound with too much tension or winding speed. You must becareful not to wind too large a coil too fast as it can fly from the winder and do damage to you or the pickup. It’s better to wind slower that to rush the job and end up with a disaster. I know as I have done it and it can take much longer to do a simple job when trying to rush.
Extra Items:
? Sandpaper: Is used for stripping the insulation off the magnet wire. It helps when soldering the magnet wire to a lead wire and keeps everything from getting too hot or cooked when making connections.
? Tweezers-I use for wrapping the fine magnet wire aroung lead wires.
? Files-For contouring the bobbins or removing burrs on flatwork.
? Brushes-For removing debris from bobbins and polepieces and finding broken magnet wire in pickups.
? Q Tips-For cleaning and chemicals.
? Adhesives-I use various glues for bonding broken bobbins and loose flatwork.
? Dun-Stunner (magnet-ager) I built this device for calibrating magnets.
? Extra flatwork and bobbins-Needed for fixing warped or destroyed flatwork.
? Bottom plates-I bring various types for Telecaster and Stratocasters that are made of steel and used to inhance the sound of the pickups.
? String-I use string for Telecaster and Single-coil Precision Bass pickups. I use white and black for restoring rewound or modified pickups.
? Switches-It’s good to have on hand a supply of 3 & 5 way lever switches for Fenders and toggle switches for Gibson’s. At times a pickup may not work and it’s due to a bad or faulty switch.
? Volume controls-I keep on hand a supply of solid and split shaft volume and tone controls. I keep 250K, 500K and 1Meg. audio taper pots. I use 250K pots for most single coil pickups to slightly redue the highend and 500K pots for most humbuckers. The Tele-Gib I built for Jeff Beck in 1974 and the one I use was made in 1976 both have 250K solid shaft-audio taper pots to give the instrument a smoother sound. Newer Gibson’s use 300K audio taper pots for the volume controls. If you use Dan Electro pickups in your Stratocaster try using the same 100K posts. The pickups are lower impedance than stock Strat pickups and should use the 100K audio taper volume pot. If you use a 250K audio taper pot with them, they will sound much brighter.
? Capacitors-I take several types of capacitors ranging from .001 mfd to .1 mfd. Standard Fenders use .05 mfd. and Gibson commonly use .022 mfd. The capacitors are basically used to roll off the top end or brightness in a pickup and Rickenbacker uses a .0047 mfd. in series to cut the bottom on the bridge pickup for that distinctive “Chris Squire” sound when he recorded with the group “Yes”.
? Tape-I use various grade of tape with special adhesives that keep from breaking down the insulations on magnet wire. I have always liked using the special # 4 Flat-back tape made by the 3M company that is no longer being used. Many manufactures have used this for protecting and insulating coils wound with fine magnet wire. Many transformer companies along with Gibson, Epiphone, Seymour Duncan have used this tape for years. We will miss it and it’s excellent working and mechanical properties.
? Check-off list of extra things to bring- I have this list for things you need extra when on the road. It’s important to have your supply of water, mints, pens and paper when doing shows. I always keep phone numbers and guest’s I have seen at various shows on this list and then put it in my computer when back home.

179. Why are pole pieces used in guitar and bass pickups adjustable and some non-adjustable? Tom Young-Los Angeles, California
Adjustable pole pieces are used to help balance the output of each string. Fixed pole pieces as used in many Fender style pickups may have rod magnet pole pieces cut to the desired length for better balance and output of each string. Early Stratocaster had pole pieces cut to a desired length for string made back then. Early electric guitars used strings with a wound 3rd or G string. Today many players use a plain G for better bending. The staggered height of the pole pieces gives the Stratocaster a particular sound because the magnets are cut to different lengths. By changing the length of each pole piece will give a pickup a particular sound. The strength and length of each pole piece will change the output and tone of a pickup. Gibson humbuckers were originally designed without adjustable pole pieces and since Gibson P-90’s (single coil pickups often called Soapbars) had adjustable pole pieces, Gibson marketing felt that having adjustable pole pieces on the humbuckers was a good selling point. Old Broadcasters, Telecasters, Esquires until 1954 had rod magnets all the same length. Leo Fender used magnets that were .625” in length. During the years of manufacturing many pickups were changed to a staggered pattern such as the Telecasters, Esquires, Single Coil P-Bass, Jaguars, etc. I like using flat poles for Telecasters because the strings being made today have better output and balance from each string. The stud side of a humbucker has about the same magnetic strength from pole to pole and the adjustable side has little effect on the output of each string when moved up or down. The stud side of a humbucker has a stronger output than the adjustable side of a standard Gibson style humbucker. The adjustable poles of a humbucker loses part of the magnetic field because it extends out the bottom of the humbucker. That makes the top of the pole piece slightly weaker than the stud side. As the adjustable screw is raised, it allows the magnetic field to be directed more towards the string giving it slightly more output. As the adjustable pole piece is raised, less extends out the bottom of the pickup and slightly more magnetic field to the top of the pole piece. Some recommend cutting the pole pieces off on the bottom, but this can usually cause damage to the bobbin when removing the poles. It will give you slightly more output and brighter pickup.

180. What does raising and lowering a pickup from the strings do to the sound of a pickup? Ed Davis-Mt. Shasta, California
I find that raising and lowering a pickup does several things. When I move my pickup closer to the strings I get more output and more attack. When lowering a pickup you get less output and a smoother sound. As the pickup is moved further away from the bridge the louder and fuller it sounds. The pickup has more string vibration moving over the coils. If the pickups are too close such as in a Stratocaster I find you get too many overtones especially on the lower strings when playing up the fretboard. By lowering the pickups on the bass side of the guitar, I have better control with less overtones. I press the strings at the last fret and adjust the pickup to 1/8th inch on the bass side of each pickup. On the treble side while pressing the string at the last fret, I adjust the height of each pickup to 1/16th inch. This usually give me a good balance especially on Stratocasters. If the pickups are too loud when using the middle or neck pickup, I generally lower them until I find the desired balance. The larger the diameter of a string will give you more output and a thicker sound.

181. I’m a new electric guitarist and can you explain what pickups are? Donny Preston-Fort Thomas, Kentucky
An electric guitar or bass pickup is an electromechanical device for tracking the vibration of a moving string made of ferrous material. The string attracts the magnetic field from within the pickup and when plucked the movement of the magnetic field through the coil(s) causes an electrical current to be generated. The signal is connected to an amplifier by means of a shielded single or multiple conductor guitar cord and reproduced over a loudspeaker.
The basic construction of a guitar are bass pickup are:
1. A permanent magnet usually of Alnico or Ceramic material used for magnetizing the string to be plucked thus generating an electrical current.
2. The pole pieces can be either rods, bar, screw or other means of conducting the magnetic field to the ferrous strings.
3. The bobbin can be a support for the pole pieces, coil and means of mounting the pickup.
4. A coil wound with a variety of magnet wire and desired number of turns
5. A bottom plate used to elevate or mount the pickup.
6. A cover is used for coil protection or means of supporting the components of the pickup inside the cover. Depending on the material used a cover can also be used for reducing unwanted electrical interference especially on humbuckers.
Basic info on single coil on Fender style pickups:
1. 6 cylindrical alnico rod magnets of a determined diameter and length. North or South top polarity for magnetic phasing.
2. Top and bottom flatwork usually made of Vulcanized Fibre. The top is usually .062” thick and the bottom is .093 inch thick. On pickups such as Jazzmasters, P Bass, J Bass the top and bottom are both .093 inch thick.
3. 2 eyelet’s for soldering the beginning and finish coil wires and connecting the hookup wires that connect to the control plate. The beginning of the coil is normally connected to the black or ground connection. The finish of the coil is normally hot.
4. Coils are wound in a clock wise or counter-clock wise direction for electrical phasing of two or more pickups.
5. Hook up wire used to connect the electrical current from the pickups to the control harness on the pickguard or control plate.
6. Single coil pickups are usually potted in a wax solution to help eliminate unwanted microphonics and feedback normally associated with playing at high volumes or using pedals that overdrive the signal to the amplifier.
7. Single coil pickups are prone to hum and unwanted electrical interference due to stray magnetic fields from amplifier transformers and florescent lights.
8. The increased number of turns on a single coil pickup will increase output and reduce highend. Over-winding pickups can make them sound muddy but with increased sustain.
9. The thicker the magnet wire the less turns can be put on a bobbin. The thinner the magnet wire the more turns can be put on a bobbin.
10. Single coil pickup can be made magnetized two ways (north or south) and wound two ways (clockwise or counter-clockwise) making 4 ways a single coil pickup can be made.
11. Pickups can be wound for bridge, middle or neck position. I call this calibration for better balance between positions.
12. Single coils can be RW/RP, reverse wound/reverse polarity so when two single coil pickups are used they will be humbucking or quieter in the selected position.
13. Single coil pickups shielded by a copper foil can eliminate a small amount of unwanted (RF) electrical interference but not hum that is generated by stray magnetic fields.
14. To help keep single coils quieter a shielded conductor from the coil to the controls should be used.
15. Single coils guitars can be noisier due to the larger transformers being used in modern amplification. Older amps with smaller power and output transformers produce less stray magnetic fields from the amplifier.
16. Single coil pickups with exposed coils should always use a cover to avoid damage to the delicate winding in the coil.
17. Magnet wire used for the coil is copper wire coated with a protective insulation to keep the turns from shorting or bare copper from oxidation that would result in failure in the coil.
18. Reversing the magnetic field in a single coil will magnetically change the polarity in the pickup. Reversing the hookup wires in a single coil will electrically change the polarity in a pickup. Reversing the hookup wires can make the magnets noisy when touched by your fingers.
19. Single coil pickups can be hand wound. Hand winding is usually when the magnet wire is guided on by hand when turned by a winding device. Automatic winding is when the coil machine has an automatic traverse to guide the magnet wire back and forth on the bobbin.
20. Hand winding has a haphazard number of turns per layer and number of layers. Automatic winding gives you a precision number of turns per layer and number of layers. Used with controlled tension the coils will be more consistent from pickup to pickup.
21. Rod magnets should not be moved within the coil on vintage pickups as the coil is wound directly around them. Movement can break the inner winding of the magnet wire causing the pickup to fail.
This is just a few things of interest with pickups...

182. What are the common failures in various types of pickups? Ken Shall-Patterson, New Jersey
1. Damaged coil. Broken magnet wire
Damage to a single turn of magnet wire will result in failure in the pickup working. You may get a thin faint signal to the amplifier but if you turn the tone control down for the particular pickup and you have no sound, that is usually a sure sign that the coil is bad.
2. Cold solder joints
This can happen if the joint is moved or if you blow on it. Often the eyelet isn’t heated enough to melt the insulation on the magnet wire. Just re-apply heat to the solder joint if you see no signs of coil damage. On humbuckers the small hookup wire connected to the coil can have a bad or cold solder joint. The humbucker coils are more delicate to work on and extreme care has to be taken when removing the insulating tape to repair or check out if the coil is damaged. Often pulling too hard can break the magnet wire within the coil.
3. Coil damage due to removal or applied covers
Covers can be filled with dust and debris from years of playing. The debris can be connected to the outer wrappings of the coil and should be left alone when all possible. On humbuckers the connecting joint between the cover and bottom plate can often snag the bobbin and tear the coil when being removed. Make sure all the solder is removed and try using solder wick. It will get rid of excess solder between the bottom plate and cover.
4. Cold solder joints at eyelet’s
Fender and replacement pickup companies use eyelet’s pressed into the vulcanized fibre and it’s the place where two connections are made. The beginning and finish of the coil is connected there along with the beginning and finish hookup wires that connect to the control plate. Inserting the hookup wire can break the beginning or finish wire in the eyelet.
5. Broken wires at eyelet’s (beginning or finish)
I’ve seen many breaks in the magnet wire from the beginning eyelet and to where it gets covered by the outer wrappings of the coil. Repairing this can be difficult. The breaks often occur from the finish of the coil to the finish eyelet. This can be repaired much easier if care is taken to remove a turn or two that ends up being inserted into the finish eyelet.
6. Movement of magnets on single coil pickups
Magnets used on early Fender pickups can have rough pits from sandcasting when the rods are manufactured. The coil is wound directly around the rod magnets and movement can snag and break the inner wraps of the coil. If this happens the coil will have to be completely unwound or removed and rewound.
7. Magnets get demagnetized
Loss of power in pickups can be due to magnets becoming demagnetized by external sources. As long as the DC resistance is measuring properly the de-magnetized magnet can be re-magnetized and calibrated to proper strength.
8. ICPC-Inner Coil Pole Corrosion
When a rod magnet corrodes and the rust breaks down the insulation on the copper magnet wire. The breakdown of insulation and the exposed copper wire oxidizes and eventually breaks, making an open circuit.
9. Faulty connections and connections at control plate or jack
Switches and controls can eventually break, get bent or wear out. This will affect the proper working conditions of pickups. Cold solder joints can happen and re-soldering will usually do the trick. Many jacks are brass and nickel plated. The plating inside the jack can wear thin exposing the brass. In time the brass can oxidize and not make proper connections to the shaft of the plug. Using a small rod and sandpaper will help wear away the oxidation inside the jack. If consistent problems exist, the jack should be replaced.
10. Bad Cords
During my early days of playing I had a hard time finding good guitar cords. I was always repairing or buying them. I made many of them too! Make sure you check all your cables and especially the connections between your foot pedals. Check the jacks on the pedals too. Many have several terminals that are used for turning the battery power supply on when the plug is inserted. If you leave the cord plugged in the battery may be drained.

183. The stock value for the Stratocaster Tone capacitor is .02 mfd. I have seen your recommendation for .05 mfd. Why do you use a higher value? Lee Goldblatt-Jamacia, NY
Fender used a .1 mfd in the drawing on their original wiring diagram. The Fender American Standard uses a .022 mfd capacitor. In late 1969 Fender started using a .05 mfd capacitor to achieve less bass when the tone control was used. I like using .05 mfd-150 volt capacitor especially when rolling the tone control for a wah wah effect. A capacitor is a passive circuit component that has two metal electrodes separated by a dielectric insulator. I’ve used a capacitor substitution box that has an assortment of selected-value capacitors arranged and connected to terminals. They can be connected to your tone controls with test clips so you can select the desired value needed. I always felt single coils needed a higher value than humbuckers that are already full sounding. Many Gibson guitars use a .022 mfd. capacitor. I’ve often used a 150K resistor and a .001mfd. capacitor in parallel with the # 2 & # 3 lug on my volume control. This helps retain the brightness as the volume is turned to lower volumes. The # 1 lug on the volume control is always grounded to the chassis of the potentiometer. You can rewire your harness for several tone modifications depending on what pickup you want the tone circuit connected to.

184. What kind of magnet wire do you like using for winding pickups? Andrea Johnson- Tacoma, Washington
There are several manufacturers and distributors of high quality magnet wire. Several distributors can insulate the magnet wire with a coating plain enamel, formvar, polyurethane and other special coatings for your particular need. I like using magnet wire that has good windability and core softness. Softness is when a coil is wound to a particular coil shape it should maintain the shape if removed and should not spring out when cut off. The shape of the coil or bobbin that it is wound on should maintain the shape and not bulge on the sides of the pickup. If the magnet wire is to hard or stiff, more tension is needed to maintain the shape of the bobbin. Having to much tension on the magnet wire when winding coils can cause the ends of the bobbins to flair. The stiffness and tension of the magnet wire can cause bobbin distortion especially when subjecting the coils to hot wax for an extended period of time. If you have any old bobbins and pot them in wax, watch how the bobbins distort. Much of the distortion is due to normal shrinkage and pressure of the coil around the inner walls of the bobbin. The pole pieces can be pulled closer together thus causing some pickup covers to be out of tolerance with the pole pieces.
Another factor is the surface of the magnet wire or insulation. The surface has to be suited for higher winding speeds and have a low coefficient to friction. This allows the magnet wire used in guitar pickups to have low friction so each turn slides into place on the rapidly wound coil. The surface should have reduced friction and no surface blemishes such as blisters, pin holes or an uneven surface. The magnet wire should be soft and have low springiness, have low friction, minimum surface blemishes and a consistent overall diameter. The diameter should not change drastically by having thin or thick areas. You can have thin and thick area’s especially when hand winding and holding the magnet wire to tight. This can stretch the magnet wire making it thinner in certain areas. Also this can cause the particular coil to have an increased DC resistance. It’s important when using automatic traverse controlled winding too. The automatic traverse is where the magnet wire is layered back and forth on the bobbin automatically to a pre-determined number of turns per layer. This depends on the overall diameter of the magnet wire and the maximum winding area on the bobbin. Try to use the best magnet wire you can find especially when winding production pickups. Magnet wire can have lubrication that allows the insulated wire to slide into place better. I’ve used cotton swabs to hold the wire when winding that’s been dampened with water, mineral oil, olive oil and have even experimented with swabs of hot wax to pot the pickup as it’s winding. A lubricated wire seems to have less microphonics than non lubricated wire. Lubricated magnet wire can slightly increase the diameter of the wire. Most of my experiments have been done when hand winding. I like hand winding because you can guide the magnet wire back and forth on the spinning bobbin.

185. What is the Gauss, Force (Oersteds) and Maximum energy of various magnets? Dr. Nick Toth-Bloomington, Indiana
I want to start by giving those interested a glossary of terms that will help you have a better understanding and terminology used in magnets and coils. It may be complicated and confusing but is a part of the science used in making guitar, bass and steel guitar’s sound the way they do. I’ve gotten a lot of help in the past from Indiana General now called UGIMAG, Inc. who have made magnets for most of the major guitar and pickup companies.
Ampere Turn: The unit of magnetomotive force. It’s a product of the number of turns in the coil and amperes passing through the turns.
Anisotropic Magnet: A material having preferred orientation so the magnetic characteristics are better along one axis than along any other axis.
CGS System: A system of measurement in which the centimeter, gram and second are fundamental units.
Coercive Force: The demagnetizing force in oersteds corresponding to zero magnetic induction in a magnetic material after saturation,
Coercive Force, Intrinsic: The demagnetizing force in oersteds corresponding to zero intrinsic induction in a magnetic material after saturation. It’s a measure of resistance to demagnetizing.
Demagnetization: The partial or complete reduction of induction.
Demagnetization Curve: That portion of the normal hysteresis loop in the second quadrant showing the induction in a magnetic material as related to the magnetizing force.
Dimension Ratio: The ratio of the length of a magnet in the direction of magnetization to its diameter or the ration of the length of the magnet to the diameter of a circle which has an area equal to the cross sectional area of the magnet.
Energy Product Curve: A graphical representation of the external energy produced by a magnet and is the product of the flux density and demagnetizing force as show on the normal demagnetization curve.
Ferromagnetic: A material which in general exhibits hysteresis phenomena and who permeability is dependent upon the magnetizing force.
Flux, Magnetic: The physical manifestation of a condition existing in a medium or material subjected to a magnetizing influence.
Flux, Density: The number of lines or maxwells per unit area in a section normal to the direction of the flux.
Gap: That portion of the magnetic circuit that does not contain ferromagnetic material like an air gap.
Gauss: The unit of flux density.
Gilbert: A CGS unit of magnetomotive force. The magnetomotive force required to produce one maxwell magnetic flux in a magnetic circuit of unit reluctance.
Hysteresis, Magnetic: A property of a magnetic material by virtue of which the magnetic induction for a given magnetizing force depends upon the previous conditions of magnetization.
Hysteresis Loop: A normal hysteresis loop is the graphical representation of the relationship between the magnetizing force and the resultant induced magnetization of a ferromagnetic material when the magnetizing force is carried through a complete cycle of equal and opposite values under cyclic conditions.
Incremental Permeability: The ratio of a change in magnetic induction to the corresponding change in magnetizing force when the mean induction differs from zero. It equals the slope of a straight line joining the excursion limits of an incremental hysteresis loop.
Induction, Intrinsic: The excess of the induction in a magnetic material over the induction in vacuum, for a given value of magnetizing force.
Induction, Magnetic: The magnetic flux per unit area of a section normal to the direction of flux. The unit of measurement for flux density in CGS system is the gauss.
Isotropic Magnetic: A material having the same magnetic characteristic along any axis or direction.
Leakage Flux: That portion of the magnetic field that is not useful.
Leakage Factor: The ratio of the total flux produced in the neutral section of the magnet to the useful flux.
Line: A term commonly used interchangeably for a maxwell.
Magnet: A body of material that has the ability to attract to itself iron, steels or other magnetic material. In a natural state it is called a Lodestone in the form of a mineral called magnetite.
Magnetic Dipole: A minute molecule that has a north and south magnetic field
Magnetic Force: The force exerted by a magnetic on a body or other magnetic material.
Magnetic Repulsion: The force that causes like magnetic poles to push away from each other. Like poles repel and unlike poles attract.
Magnetizing Force: The magnetomotive force per unit length at any given point in a magnetic circuit. The CGS system the unit is the oersted and defined by the equation:
Magnetizing Force = Magnetomotive force in gilberts ? Length in centimeters
Magnetic Induction: When magnetization of a magnetic material such as steel or iron when placed near or within a magnetic field.
Maxwell: The CGS unit of magnetic flux.
North Pole: The north pole of a permanent magnetic is that pole which is attracted to the geographical north pole.
Oersted: The CGS unit of magnetizing force.
Permeability: The ratio of the magnetic induction in a given medium to the induction which would be produced in a vacuum with the same magnetizing force. In the CGS system permeability is given the equation:
Permeability = Magnetic induction in gausses ? Magnetizing force in oersteds
Permeance Coefficient: The ratio of the magnetic induction to its self demagnetizing force.
Reluctance: The reciprocal of permeance.
Remanence: The magnetic induction which remain in a magnetic circuit after the removal of an applied magnetomotive force. If there is an air gap in the magnetic circuit, the remanence will be less than the residual induction.
Residual Induction: The magnetic induction corresponding to zero magnetizing force in a magnetic material after saturation in a closed circuit with no air gap.
Saturation: The condition under which all elementary moments have become oriented in one direction. A magnetic material is saturated when an increased in the applied magnetizing force produces no increase in intrinsic induction.
South Pole: The south pole of a permanent magnetic is that pole which is attracted to the geographical south pole.
Stabilization: The process of subjecting magnets to various conditions such as heat, or demagnetizing conditions so that magnet will produce a constant magnetic field.
Tractive Force: The force which a permanent magnet exerts on a ferromagnetic object.

Magnetic material Gauss Oersteds Max. Energy
Alinco 1 7200 470 1.40
Alnico 2 7500 560 1.70
Alnico 3 7000 480 1.35
Alnico 4 5600 720 1.35
Alnico 5 12800 640 5.50
Alnico 5 DG 13300 670 6.50
Alnico 5-7 13500 740 7.55
Alnico 6 10500 780 3.90
Alnico 7 8500 1040 3.7
Alnico 8 8200 1650 5.30
Alnico 8 HC 7200 1900 5.00
Alnico 8 HE 9100 1600 6.0
Alnico 9 10500 1500 9.00
Alnico 2-sintered 7100 550 1.50
Alnico 5-sintered 10900 620 3.95
Alnico 7-sintered 6200 1000 2.2
Alnico 8-sintered 7400 1500 4.00
Alnico 8-sintered HC 6700 1800 4.50
Ceramic 1 2300 1860/3250 1.05
Ceramic 2 2900 2400/3000 1.80
Ceramic 5 3800 2400 3.40
Ceramic 7 3400 3250/4000 2.75
Ceramic 8 3850 2950/3050 3.50
Cunife 1 5500 530 1.40
Vically 1 7500 250 .80
Samarium Cobalt 18 8700 8000 18.00
Samarium Cobalt 20 9000 8700 20.00
Samarium Cobalt 22 9500 6500 22.00
Samarium Cobalt 24 10300 5500 24.00
Samarium Cobalt 26 10000 6300 25.50
Samarium Cobalt 30 11000 5200 30.00
Neodymium 24.5 10200 9200 24.50
Neodymium 27 10800 9500 27.00
Neodymium 28 10800 10100 28.00
Neodymium 32 11600 10800 32.00
Neodymium 35 12300 9250 35.00

186. What are some things to check why a pickup doesn’t work? Tom Coleman-Pennsgrove, New Jersey
There are many things that can cause a pickup to be inoperative. Pickups don’t always have to be used and abused for them to fail. Here are some things to check.
? Broken magnet wire from the beginning eyelet or pigtail*: On Fender style pickups the beginning magnet wire is connected to one of the eyelets. The beginning of the coil is wound from the inside and finishes on the outside. It can be difficult to repair the beginning wire if it is broken next to the coil. If the magnet wire is broken near the eyelet, there is a chance the magnet wire can be extended by soldering an extra length of conductor and connecting it to the eyelet. Becareful soldering it to the eyelet and remove excess soldering flux. Extreme care needs to be done when repairing all types of single coil pickps. On early Gibson style single coil and humbucking pickups, the lead wire begins inside the bobbin and extends through an exit hole to be hooked up. It will be difficult to repair if the problem exists with the pigtail inside the beginning of the coil. At times there can be a cold solder joint or break at the beginning of the coil where the magnet wire and lead wire are pigtailed. The coil will have to be completely unwound, repaired and rewound again. Don’t distroy the original wire to do this. It can be re used.
? Broken magnet wire from the finish eyelet or pigtail*: On Fender style pickups the finish wire connects to the other eyelet. If the magnet wire is broken at the eyelet or outer part of the coil, repairing can be made easier. I carefully use a heat gun to soften or remove hardened wax on the outer turns of the coil. I can unwrap as many turns needed to find the break and then reconnect it to the finish eyelet. If the pickup still doesn’t work, then more turns need to be removed to see if there is an external break. I use a fine tooth brush to loosen the break in a coil. At times I use a chemical solvent to remove the outer layers of magnet wire on Fender style pickups. Chemical solvents such as lacquer thinners should be used with extreme care always use a protective eye covering used when soldering or using chemicals. If there is no break visible after examining the coil then the pickup could have ICPC which is listed below. Heat guns and chemical solvents should not be used on plastic Gibson style bobbins. The heat and chemicals can distort and dissolve the bobbin material. If you need to remove old tape that is gummy or sticky, I use lighter fluid as a cutting agent. Use sparingly and wipe off excess fluid.
? *Pigtails: The connection between the insulated magnet wire and hookup wire. I use between 28 & 30 gauge stranded hookup wire for most connections in humbuckers. They are usually the black and white wires used for connecting two bobbins in a humbucker in series or used with single or 4 conductor shielded cable. When connecting the hookup wire, I find it best to sand the magnet wire with 600 grit sand paper to remove the insulation on the magnet wire so soldering (pigtail) is made easier.
? ICPC- Inner coil pole corrosion: Most often on Fender single coil pickups, moisture and condensation can occur inside the bobbin. Playing in hot sweaty nightclubs with moisture at times soaking the pickups can cause major problems down the road. The moisture can cause the magnets to rust and particles of oxidation begin to break down the insulation on the magnet wire. When there is insulation breakdown on the magnet wire, the non insulated copper wire can oxidize and deteriorate. On Fender style pickups, the coil is normally wound directly around the magnets. When the magnets rust it promotes breakdown of the magnet wire. Moisture can be absorbed in the lining of the guitar case and when exposed to high heat or sunlight, condensation can take place within the case.
? Guitar string snag under the lip of the pickup: When playing hard your high E or low E string can snag the edges of the bobbin when there are no covers to protect the coils. I see this often especially on Telecaster rhythm pickups when players remove the covers. This leaves an exposed coil which is subject to string or pick damage. During the 60’s Jeff Beck started the fad of removing covers from his Gibson humbuckers. Soon after that many players started using lighter strings which have less tension and bend easier. The lighter strings, tension and exposed humbuckers contributed to the strings getting snagged under the outer edges of the bobbins. This happens more and more with guitars equipped with tremolo’s that can drastically loosen the strings. The loose plucked string is more likely to get snagged under the outer edges of the pickup so extreme care while playing needs to be used. If you desire not to use covers make sure you don’t damage the coils. Breaking one turn of magnet wire will make the pickup non functional.
? Bent contacts on switches: The 3 & 5 lever switches used on the majority of Fenders have contacts where many pickup and circuit connections are made. On the early Centralab 1452 lever switches the contacts are connected to the phenolic wafers by small brass eyelet’s. The contacts are precisely bent so the wiper blade inside the switch makes proper contact. At times when working on your pickups the contacts or solder connections can get bend making the pickup selection non functional. The contacts need to be carefully inspected and realigned for proper contact. It is best to used a Volt-Ohm meter to check continuity. I use small round needle nose pliers to re-shape the contacts. On Gibson style toggle switches the contacts can be easily aliened for proper connections
? Worn or oxidized contacts on switches: The constant movement of switches can wear thin the contacts and replacement may be necessary. If switches are not used an extended period of time, oxidation can build up on the contacts from extreme moisture in the instrument case or high humidity. A special contact cleaner for switches should be used to remove, clean and lubricate the contacts. Check with your local electrical supply or Radio Shack for proper solvents for cleaning contacts. Always be careful not to overspray and get the solvents on the finish of the instrument. Properly cover and mask off the instrument. Be careful using certain adhesive tapes as the adhesive can react with the finish of the instrument. Check with your local tape dealer for specific tape recommendations.
? Grinding pole pieces: I remember during the 60’s many players were trying to level the pole pieces on their newer Telecasters to simulate the flat poles of early Fender Broadcasters, Esquires and Telecasters. I’ve received many pickups in for rewinding because the coils stopped working. I found that the grinding of the magnets caused the pole piece to get so hot that it cooked the insulation on the magnet wire. In time the exposed copper wire would oxidize and the DC resistance would change then stop working. Remember that the magnet wire on most single coil pickups are wound tightly in contact with the rod magnet pole pieces. Grinding the magnets can also degauss or weaken the particular pole you are grinding. Also grinding magnets can leave small particles of magnet dust that can eventually vibrate and may cause pickup to be microphonic in extreme cases.
? Movement of the cast magnet rod pole pieces on single coil pickups: Earlier rod magnets in Fenders are sand cast and have pits and rough sides. Most all Fender style single coil pickups have the magnet wire wound directly in contact with the rod magnets. Moving the magnet will snag and break the tightly wound coil especially on the early Fender pickups. Moving the magnets to change the height of the polepieces on newer Fender style pickups is possible but I wouldn’t recommend this be done. I never move the outer pole pieces because there is maximum pressure at both ends and is where the bobbin supports most of the coil tension. There are some nylon and plastic molded bobbins which allow the movement or rearrangement of the rod pole piece. I never change the pole height on Fender Telecaster style pickups that have a ferrous bottom plate. You can’t press the extended pole pieces down on those type of pickups with the ferrous elevator plate in place. Applying extreme pressure on magnet can cause them to crack. I wouldn’t try moving pole pieces without the proper tools as extreme damage can result. Never insert magnets into bobbins as it will likely break the exposed coil inside and if you use older Fender magnets, be careful as they may be a larger diameter.
? Magnetic field re-oriented: You need to be careful not to have your pickups near any AC sources that could change the orientation or domains within your magnet. The magnetic field on a rod pole piece is normally South on one end and North magnetic polarity on the opposite end. Depending on the outside source such as motors, solenoids or other AC current sources can change the alignment of magnetic orientation. On bar magnets such as the ones used on Gibson style humbuckers the magnets measure on average 2.5”(L) x .5”(W) x .125”(T). The magnet is magnetized across the .5”(Width). One side is North and the other is South. Most bar magnets used in humbuckers are Anistropic or having a preferred direction of magnetization. If a magnet is reversed in one pickup and used with another, it could be magnetically out of phase. The thin bottomless sound makes you think you have a bad pickup. This can be easily solved by reversing the magnet or reversing the electrical phase then check to see if you have a full round sound when two or more pickups are used.
? Magnetic phasing per pole: I’ve seen rewinds come into me where the customer decided to flip flop magnets in their single coil pickups. I had a pickup come to me where the top magnet polarity was (S) (N) (S) (N) (S) (N) and the pickup was completely out of phase with itself and from string to string when using a combination of pickups. Another pickup had the top polarity (S) (S) (S) (N) (N) (N) with the player thinking it would make it humbucking. You need to use either all (S) or all (N) magnetic polarity in single coil pickup where one coil is used.
? Magnetic field improper phasing: Another big problem is when you combine pickups from different manufacturers. You need to get proper phasing both electrically with coil direction or magnetic phasing with magnetic orientation. When using a combination of pickups test’s need to be made and discussed in a future article on how to determine the phasing of each pickup. I will show you how to test magnetic polarity and electrical phasing using your volt-ohm meter. You can use phase switches or have all the pickups in phase using proper hookup with various magnetic polarities.
? Magnets degaussed: Having a magnet that is degaussed will make your pickup have less output and sound warmer. It can be caused by extreme heat, shock, alternating currents and other environmental conditions. The size and shape of a magnet will determine how stable a magnetic field will be and recharging a magnet in a pickup if desired will often make the pickup sound brighter and have more output.
? Low DC resistance in pickup: At times there’s internal breakdown inside the coil because of insulation fatigue that causes shorting of several layers of magnet wire. This breakdown can reduce the DC resistance of a pickup. I’ve seen this happen with resin potted pickups and four conductor pickups where the wires can short out with each other during final hookup. Make sure you measure pickups one at a time and not in combination with others. If a pickup is used in combination with other pickups or circuit there will be inaccurate DC readings per single pickup. It’s best to use high quality materials and especially insulation’s on magnet wire. Thicker insulation’s will have better reliability than thinner insulation’s and less likely to fatique.
? Pickup sounds thin with no bottom: When a single pickup sounds thin with no bottom is usually a sign that the pickup has a broken coil. If you get little signal and turn your tone control to zero and you get so sound, this is usually an indication that the coil is bad. Also check to see that the components such as switch, capacitors and circuit are all hooked up properly. The coil will have to be inspected to see what the problem is and if it can be repaired without rewinding.
? Humbucking pickup sounds thin when used by itself: This can be a sign that there is a damaged coil or even the wiring inside the pickup is not correct. If the wiring inside the pickup rewired you can have a phase problem. Normally the two finish wire of a humbucker are hooked together. The beginning adjustable coil is grounded and the beginning stud coil is positive. The adjustable side of the humbucker is normally South magnetic field and the stud side is North. The actual coil direction of each bobbin must be determined to make sure the coils are hooked up for proper wiring. If you look at the top of typical Gibson bobbins, the coil is wound counter-clockwise around the bobbin.
? Potentiometers-effects of wrong value: Make sure the potentiometers are of proper value and working correctly. Make sure they are clean and oxidation free. Make sure the capacitor is hooked up properly and of the proper value. Fender Telecasters and Stratocaster normally use a 250 K audio taper potentiometer. Gibson originally used 500 K audio taper potentiometers for both volume and tone. Since the 70’s Gibson used 300 K audio taper volume controls. If you use a 100 K audio or 50 K audio the high end on the pickup will be drastically reduced. If your using a 250 K audio taper and need a slightly brighter sound, try using a 500 K audio or a 1 Meg audio taper potentiometer. To retain the clarity in your pickups when turning the volume down, you can use a .001 mfd. capacitor between the # 2 & 3 lug of your volume potentiometer. You can also put a 150 k resistor in parallel with the .001 mfd. capacitor. Normally the # 1 lug is grounded to the chassis of the potentiometer.
? Removing covers: During the 60’s and 70’s the fad was to remove the covers from your humbuckers. Many wanted to see if they had those famous double cream Patent Applied For humbuckers designed by Seth E. Lover for Gibson during the mid 50’s. Jeff Beck removed them so he could get more output and height adjustment from the pickups. He also told me that he removed the cover so he would have less microphonic feedback when playing at higher volumes. Many players and repairman had problems getting the cover with jagged solder joints off the pickups without destroying the coils. The solder residue from the covers snagged many coils and caused complete failure in the pickup. I was upset to see so many pickups badly rewound because of just one broken wire on outer turns of the coil. The whole coil doesn’t need to be rewound but carefully repaired. You need to remove a few turns to find the broken wire and rejoin a new section, rewind a few turns, insulate and hook back up. A solder wick should be used to absorb the excess solder holding the cover onto the bottom plate. Keep the old covers in a drawer for future use when removing it. Removing old covers from Stratocaster pickups should be done with care as moisture and grime over the years can cause the cover to stick to the coils. Damage can result if trying to pull the covers off. I’d leave the covers on unless there was an extreme need for them to be removed. Pickups are fragile and should be handled carefully. Covers should always be kept on pickups with exposed coils.
? Careless handling: Over the years many working pickups were removed from instruments and thrown in boxes or tossed in a drawer. Bottom plates or misc. pickup parts could hit the coils breaking the exposed windings or cracking bobbins. When pickups are removed from an instrument they should be carefully wrapped in tissue and even aluminum foil to further protect them. They should be labeled and put in a safe place for further use. Remember the pickups of today will be the vintage of tomorrow.
? Improper hookup: If you work on your pickups or have other do custom work for you, make sure they are qualified and are careful with your pickups. The pickup is the heart of the instrument and if the pickup is damaged in any way the performance of the instrument will be diminished. Each time you work on your instrument, make a drawing and keep the wiring available. The worst thing when working on your guitar is to have it all apart and then you get that phone call. When you get back you’ve forgotten where the wires went. I get calls all the time from players and repairman trying to rewire guitar. Make sure all the wires are connected and soldered correctly and leave enough wire for connections to the jack and other hardware. Don’t pull and stretch wire and it can bend the delicate contacts on switches and also bend them where they could short out with each other.
? Environmental conditions: Don’t leave your instrument unattended where someone else can get a hold of it or knock it over. Keep it away from little kids, cats and dogs and out of direct sunlight. Never leave an instrument lying next to a heater or window where some passerby might like to borrow it! Don’t keep the instrument in extreme cold or inside your car truck that can get very hot. Never use steel wool to clean your frets as the fibers will be attracted to your pickups. It’s a mess to remove the fiber’s and can cause other problems when your playing. You can get steel wool stuck in your fingers which can cause awful irritation.
? Soldering insulation’s: Insulation’s on magnet wire come in various thermal temperatures. Some take moderate heat to melt and some take much higher temperatures. Using to high of a temperature and actually anneal the copper magnet wire that can cause it to fatigue at a later date. I like sanding the insulation’s first as it reduces excessive heat that could damage other pickup components. Sand the wire before inserting the beginning wire into the eyelet on Fender rewinds to reduce the cooking effect it has on the surrounding vulcanized fibre. Always use proper ventilation and eye protection. Wipe off excess flux with alcohol or flux cleaner and dry.
? Faulty conductor inside insulated hookup wire: I have seen insulated hookup wire with invisible breaks inside. You should always use an ohm meter and check at various points in the pickup connections or contacts. Always check both ends in a hookup wire. I once had a pickup that worked at the eyelet’s but when I hooked it up to the switch it didn’t work. Another time I remember checking the two soldered eyelet’s on a Stratocaster pickup with my ohm meter and the pickup showed a complete short. I almost thought the pickup was shorting inside when I noticed the ends of the cloth braid hookup wire were accidentally touching each other. Always double check any possible connections before deciding the pickup may need repair or rewinding.
? Color coding of various pickups: When putting pickups in your instrument, make sure you are using the proper color code for the particular manufacturer of the pickups. Many companies have their own way of hooking up pickups and if you use the same color code that was previously in the instrument, it may not work. That’s why it’s important to have work done by a reputable dealer or repairman as they will have all the necessary technical information to make your instrument work properly.
? Cold solder joints: The majority of pickup failures that I’ve seen have been cold solder joints. This is usually caused when there is high production in manufacturing pickups and not enough time is taken for proper soldering. Heating and cooling of solder joints can cause them to expand and contract. The coil may work at first as the heat melts the insulation on the magnet wire. After time if there are pits and voids in the solder joint the bare copper can oxidize and eventually not make a proper contact or the copper magnet wire can break. Usually reheating the joint with proper temperature the time duration will help solve the problem and restore the pickup to proper operation. If you use too high of a temperature, the solder can boil and leave minute air bubbles that can eventually oxidize or corrode. Take your time and always use a rosin core solder not acid core that is used for plumbing.
? Faulty volume control: The hookup wires from the various switches eventually go to the volume potentiometer to adjust the output voltage of the instrument. Many times when soldering hookup wires to the contacts can cause the solder to travel down the lug and short out with another lug. Normally the # 1 lug on the volume control is soldered to the outside chassis of the volume control. Soldering to the outside chassis of the potentiometer can cause extreme heat to travel through the elements inside the pot. The extreme heat can cook the resistance element causing it not to work properly. Extreme use and oxidation on the sweeper contacts can cause the pickup to cut in and out. Worn resistive elements need to be replaced when volume is no longer working properly.
? Potting solutions: Potting is embedding a pickup in a resin or hot wax solution to help eliminate vibration or eddy currents in a pickup that can cause microphonic feedback. Potting resins have been known to shrink and breaks the magnet wire or some element in the circuit inside the pickup. Most potting resins have a thicker viscosity to saturate or permeate a wound coil and are often used to encapsulate the circuit and components of a pickup to avoid tampering. Resin potted pickups allow not further modification or rewinding. When pickups potted in a resin or epoxy and stop working, pickup replacement is needed. Warming the resin potting solution helps thin the viscosity. There needs to be a relationship to temperature and time duration when wax potting a pickup. If you leave a plastic humbucking pickup to long in hot wax, the pressure from the wound coil can distort the pole spacing, bobbin shape and cause the pickup to fail. If you wax pot a Fender style pickup too long or at to high a temperature the wax can seep back out still leaving the pickup still microphonic.
? Incorrect wiring of circuit: Make sure you have all the wires connected to the proper contacts and everything is grounded properly. Follow the procedures or schematics for the particular instrument or pickups. Check for proper solder joints, connections to switches and grounds. Make sure the wires on the connections don’t have strands accidentally touching other wires or shorting out. When wiring in new pickups, use the proper procedures recommended by that manufacture. Double check any custom schematics and wiring diagrams for accuracy. If in doubt, call the manufacturer or custom shop.
? Mounting screws shorting out wiring circuits: Be careful when screwing in pickguard or mounting ring screws that are to long. They could be screwed into a cavity or channel where the hookup wire goes through and short out a component. I’ve seen pickups work before being installed in an instrument and stop working after all the assembly hardware is put in place. The humbucking mounting ring screw shorted out the pickup cable.
? Faulty Jacks: Most jacks are nickel or even gold plated. If the plating wears off the jack from constant use it leaves the inside unplated. The unplated brass can oxidize from moisture and outside elements causing improper connections between the shaft and inside wall of the jack. This can cause the guitar to be intermittent and one might think failure in the pickups. Double check the jack and clean or replace if necessary.
? Faulty Ground: On several Fender instruments the jack is grounded to a thin aluminum shield underneath the pickguard. I’ve seen oxidation so extreme that the connection between the lock washer between the jack and aluminum shield made improper contact causing the instrument to fail. You couldn’t get a proper reading and the jack assembly had to be removed cleaned with a contact cleaner using a fine brass wire brush and reassembled. Make sure there are proper ground connections between the potentiometers, switches and pickups.
? Bad guitar cord: I’ve had guitars sent to me that worked fine to find out that the musician had a bad guitar cord. Do routine checks of your guitar cords, connections on your foot pedals and accessories. Always keep extra cords around too as there seems to be somebody always tripping over them.
Amplifier not working: This is another important one to check. This may sound funny but make sure your amp is plugged in and have power. Make sure someone didn’t borrow your fuse holder and your standby is working condition. I had a bass player use my amp at a practice and blew out the speaker without me knowing it. I played my guitar and thought my pickups went bad till I checked it with another amp. Probably my number one rule is don’t let anybody use your equipment. I’ve had band members borrow my tubes, speakers and even borrow a volume potentiometer.