How To Repair A Jack Plug

How To Repair A Jack Plug

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  1. Many guitar repairs follow the old electronics adage:  "First, make sure it’s plugged in."  Many electronic repairs are simple to fix.  One of the most common for electric and acoustic guitars alike, is a broken jack.  This 1/4 inch jack is your only connection to your amp.  Fixing an amp jack short is not a hard task for most hands-on people.

    Acoustic Guitars

    The most common problem with an acoustic guitar with an internal pickup microphone, is dropping it with the jack still inserted.  First, a word of caution about dropping an acoustic guitar.  The bracing inside the body is acoustically tuned.  dropping an acoustic guitar could cause a failure or breakage of this bracing.  At best the body of the guitar will develop a buzz.  At worse the neck could start bending upward because of the lack of support.  This is a very expensive repair!

    Now most often the jack itself hasn’t suffered too much damage.  To find out, first remove the retainer nut from the shaft of the jack.  Of course, you should have already unplugged the amp cord as well.  For many acoustic guitars, the jack and the strap button are one and the same.

    So you will need to remember that this is a moderate to expert repair. If you are uncomfortable with this you should find a reputable luthier instead.  Most music stores have repair men either on hand or can direct you to a reputable builder.

    If not, and you are ready to attempt this, then proceed by removing the splintered wood, but do not take away too much material because a repair is always going to be more visible.  If you have an Ovation or similar plastic "turtle shell" backed guitar, just remember that you are working with plastic rather than wood.  You will be using plastic as filler and heat or a chemical glue to melt the plastic back together.  A wood backed guitar will be using wood, guitar glue and wood filler for your repair.

    While the jack is apart, inspect it for separation from the cord end when inserted.  The jack will have a metal tang that will push against the jack as it is inserted.  It is very important that his springy piece of metal maintains contact at all times with the male end of the cord.  Simply bend it to adjust.  Also inspect the solder joints to the jack.  If they are frayed or broken, trim the wire and resolder.  Also be sure to adjust your backing nut for the material that you are using for your repair.  If you do not do this now, you will not have room to thread the face nut on when the repair is complete.

    Make sure you have a solid area to glue your repair pieces to.  Yes, I said "pieces."  You are going to glue in a primary piece of support material to help make the repair more solid.  This piece should be larger than the repair and applied inside the body of the guitar and held in place while the glue sets, by using long slender pieces of wood that can be bowed into the sound hole and propped against the opposing side of the guitar.

    If for some reason you don’t have a sound hole, such as the Ovation iDea, you should allow a luthier to repair the guitar.  Likely the luthier will have a technique that will not involve removing the face of the guitar, or will have specialized tools for working through the electronics hole instead.

    Once the backing piece has been set, make sure to play the guitar with the strings in tune to make sure you have no buzzing.  As this will need repaired first before moving on. Trim your repair material, trying to match the grain of the wood or plastic as closely as possible.  Don’t worry yet about the hole for the jack, we will be drilling a 3/8 inch hole later.  Right now fill the whole area.  Now glue in your final repair piece.

    Once this piece sets, determine how much filler you will need.  The plastic guitars will need to have plastic heated, or chemically melted to apply to the area and smoothed in with a burnishing tool.  The wood guitars will need wood filler applied according to the instructions and allowed to dry.

    The wood guitar is now ready to be lightly sanded and re-clear-coated.  The plastic guitar should be checked for warping from the heat applied to glue the pieces together.

    Once the fit and finish is satisfactory, then drill your 3/8 inch hole.  Please use great care to set a depth and not drill to far.  Damage to the inside of the guitar could be very expensive at this point.  Now using the clamp bows that you used earlier push the jack through the hole from the back side.

    Electric Guitars
    Most electric guitars because of the harsher typical environment that they tend to endure, are more likely to need a jack replacement.  But more often repairing the output jack is typically more just a simple tightening. 

    First pull the jack from the guitar.  For some guitars, this will mean unstringing the guitar and pulling the pick guard from it as well.  However, most guitars are usually accessible from a cover plate on the back of the guitar or a separate cover from the pickguard on the face or back curve of the guitar.

    The 3/8 inch outer ring is held in place by typically a 1/2 inch nut.  Many times this nut has no lock washer, thus with the normal twisting of the cord it can work loose.  My first fix is to make sure it is reassembled with a lock washer on the back of the spacer nut, to keep the jack from turning inside the guitar and one on the outside, under the tightening nut, to make sure the outside nut stays tight.

    But before you reassemble the jack, inspect it for common damage.  Look at the metal tab, already explained in the acoustic section, for being bent or broken.  If it is bent, you will have times of a momentary loss of signal.  If it is broken it will obviously make no sound at all.  This could mean a simple bending of the tab back to the original position, which will also hold your cord plug in place better, or a total replacement by soldering in a new jack.

    Now, trace the output wires, the two or three wires that run from the internal electronics of the guitar.  Better guitars will have a actual cord with the wires shielded by the ground and you will not see the individual wires until they are soldered to a connection.  I have seen these as white, black and grey jacketed wire.

    Check the solder joints.  What you are looking for is frayed wire, loose solder, and disconnected or broken wire.  All of these conditions will need to be trimmed, stripped and resoldered.  Look for signs that the jack has been twisting inside the guitar.  If it has then you should also be looking for the same damage on the internal side of the guitar.

    What if a wire is broken loose and you can’t tell where it came from.  Well first, Google for a wiring schematic for your guitar configuration.  I can offer a few tips to look for but there are so many ways to wire a guitar based on how many volume controls, individual switches, active electronics that it would be impossible for me to tell you without seeing the guitar first hand.

    But, most of the time on 80% of standard wiring, the sleeve of the plug will be soldered to the ground and the tip will be soldered to the middle tab of the main volume potentiometer.  Tone pots will have a capacitor soldered with them.  Volume pots typically will not.  All of the grounding points on a guitar are usually connected together.  The back case of the pots, the spines or cases of the switches, the frames of the pickups.  You should even have a ground wire going to the tailpiece somewhere.  On most tremolo systems, like the Floyd Rose style, it will be soldered to the spring mount perch.

    Now test your repair before buttoning the guitar back up.  Slip a cord back in, turn on your amp and strum.  No sound means something else is wrong, but if you put everything back the way you found it, you should have a good sound coming from the amp.  Unplug your amp and tighten everything back up.  And it would be a good thing to test it again before going to a gig and plugging it in for the first time.

    Congratulations!  You just saved yourself some money by repairing that output jack all by yourself.

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