Electric Guitar Repair 101
Life's too short to play a less-than-wonderful guitar ...
by Chris Loeffler
Your guitar is your tool for making music, so it makes sense you want it performing in top shape and to your preferences. Even the best instrument needs occasional attention. Using a car as a metaphor for a guitar, you buy it and either accept it as it is or make customizations to your preferences. Once you’re good to go, you’ll need to do a bare minimum of regular maintenance, like tuning (put gas in it), and semi-regular care like changing strings (oil change) to keep it running. That said, over time, humidity, string gauge changes, temperature, storage methods, and regular playing are going to affect your guitar's physical condition, and just like a car might need a timing belt replacement or new starter after 100k miles, your guitar is going to require deeper attention.
This article is meant to be a brief discussion of what to look for in your guitar that suggest it’s time for maintenance, and is by no means a replacement for an experienced, qualified luthier. It’s hard to undo certain types of damage done in the name of “repairing” a guitar, and even self-proclaimed guitar techs have been known to butcher a guitar through an unhealthy combination of arrogance and ignorance. Visiting the car analogy one last time, you may not need to know how to replace an alternator, but narrowing your car not starting down to a bad starter or alternator will make you that much more informed when you call the shop.
Starting with the Basics - Action Adjustment
If you guitar just doesn’t feel right, or there’s noticeable fret buzz, start by looking at your action. Adjusting the action isn’t really a repair technique, but it addresses so many issues players have with their guitars that they think requires repair that it at least merits a quick discussion. The action, or string height from the fretboard, is typically measured at the 12th fret, although the 1st fret can also be used as a reference point (measuring both can help identify other potential culprits to string buzz and intonation). Action is a preference, and there's no industry standard to setting action other than to make sure it’s not too high as to be unplayable, or so low that the strings make contact with the frets. The easiest (and basically the only) way to address action is to set it at the bridge, based on the particualr guitar’s instruction manual..
Dialing it In - Intonation
A poorly intonated guitar will gradual ring out of tune as you player higher on the fretboard. To test intonation, tune your guitar using the harmonic on the 12th fret of each string, then play the fretted note on the 12th fret (no harmonic). If the fretted note reads flat compared to the harmonic, the scale length needs to be shortened; if the fretted note reads sharp, the scale needs to be increased. Adjustments to the bridge will address this. Armed with which strings need adjustment and what direction they need to be corrected, your guitar’s manual should be enough to tell you which way to tweak the bridge.
Wires and Magnets - Electronics Repair/Replacement
If there’s a problem with your guitar's signal, whether it be intermittently cutting out or creating scratching noises when turning knobs, you can bet the problem lies under you pick guard: pickups, selector switches, pots, and wire. If you’re experiencing signal cuts, it’s likely a wiring issue. You can often diagnose potential weak spots with your eyes - look for sketchy-looking solder connections, damaged wire, or areas that are clearly experiencing physical movement (especially near the output jack). Flow some solder on the afflicted area and you’re likely golden…you can always remove and reflow solder, just make sure your aren’t touching the solder tip directly to any components to ensure you don't burn them.
Scratchy or crackling noises when you turn one of your volume or tone knobs? Almost certainly a dirty or bad pot. If you can identify the knob that’s causing the issue, simply remove the knob and spray Caig's Deoxit (or other cleaner) into the pot where the shaft turns, and then turn the shaft back and forth for 30 seconds or so. It doesn’t take much spray to make a difference, and if this doesn’t eliminate the crackling sound, you’re likely looking at a bad pot that needs replacement.
Pickup swaps are fairly common modifications, but the need to replace a pickup due to operational issues is extremely rare. That said, the typical pickup swap is something anyone with a wiring diagram (available on most guitar manufacturers’ sites) and an hour of soldering experience should be able to accomplish. As long as you practice standard soldering technique, it'd be hard to do something you couldn't undo.
I’m going to skip body and fretboard binding repairs, because those merit much more information and experience than a brief article could address - as well as a steady hand, "super" glue, and a lot of toothpicks.
For further reading, we recently published an article (with some great feedback from community member Tonic2000) on what goes into setting up a guitar. Remember, nothing can trump experience when it comes to doing something right - but knowing what to look for, and what to do to correct issues, makes us all better customers and instrumentalists.
Chris Loeffler is a multi-instrumentalist and the Content Strategist of Harmony Central. In addition to his ten years experience as an online guitar merchandiser, marketing strategist, and community director he has worked as an international exporter, website consultant and brand manager. When he’s not working he can be found playing music, geeking out on guitar pedals and amps, and brewing tasty beer.