First, let's take a look at the guitar neck. Most guitar necks over time will warp because of the constant string tension. If your guitar has become harder to fret (pushing the strings down with the left hand to create chords) it may be a sign the neck needs adjustment. To check for warping remove the guitar strings from the bridge, not the tuning keys, this way you can put them back on without restringing. Take a yardstick and lay it edgewise across the neck. It should lie evenly across the frets. If not, then the neck needs adjustment.
Now that you have established the neck is warped. Check for a hex nut inside the body of the guitar or under a little coverplate in the headstock (the part of the guitar where the tuning keys are found.) This hex nut is connected to a metal rod called the trussrod. The trussrod runs through the neck of the guitar. By tightening or loosening the trussrod you can adjust the neck.
To adjust your guitar neck you need to tighten the trussrod by turning the nut clockwise. Sounds easy enough doesn't it? But wait, if you over tighten it you can break the neck, and that would be a bummer. So, turn the nut one half turn clockwise and let it sit overnight. In the morning check the neck with your yardstick. If it is still warped do the procedure again each day until the neck is straight. I know this may take awhile, but it's better to be safe than sorry. After all, we are trying to avoid costly repairs not create them.
Now that the neck is straight the next step is to check for uneven frets. Often you will hear "buzz" in your guitar caused by loose frets. To check for loose frets press the ends of each fret with the tip of your finger and check for movement. Since you will have to press down hard I suggest you use the point of pliers, but be careful. To repair loose frets first determine which end is loose, place your guitar on its side and hold down the loose fret. Use one drop of super glue or similar product and let it run down between the fret and the fingerboard holding the fret down while it dries. Again, this is not a hard procedure but if you are careless you will cause more damage than what you had to begin with.
Straightening the neck and gluing down loose frets should take care of any string "buzz" you may have. However, if after performing the above repairs you still have string buzz you may need to adjust the action. Adjusting the action is simply lowering or raising the string height above the fretboard. Again, I am dealing with the acoustic guitar not the electric. To adjust the action remove the strings the same as above. Remove the guitar saddle (the white plastic piece that the strings ride on) and place a piece of thin plastic inside the bridge where the saddle sits. This will raise the strings above the fretboard and hopefully stop the string buzz. This will take some trial and error because you may raise it to high and make the fretting harder. So take your time and when it feels right stop.
To adjust the action on an electric guitar screw in or out the hex nut located under each string on the bridge. This will lower or raise each string individually. So, Be very careful while performing this adjustment. If you raise the string height to much you may change the intonation of your instrument. If the string is to low it will cause a fret buzz.
So there you have it, all the tools and information you need to perform the basic repairs yourself. As with anything in life it will take time and patience. But with a little practice you will be able to perform all the repairs yourself.
Source : essortment.com
