How To Tell If A Guitar Neck Is Warped
Created with the help of Dan from HappyNewGuitarDay.com.
Do you think that your guitar neck may be warped or twisted?
The guitar neck may be warped if there is a noticeable change in the guitar’s action from string to string. Another sign of neck warping is an irregular gap between strings, more so in the higher strings than the lower ones.
Sighting The Neck
To detect that the guitar neck is warped, place the straightedge of a ruler along the edge of the fretboard while looking down on it. Place your eye directly above or below the fret, and look down along where the ruler and nut meet. You may need to repeat this process a few times if you are not used to it initially. The straightedge must extend past each end of fretboard by about a half inch to get complete accuracy in your evaluation.
Fixing A Warped Guitar Neck
HappyNewGuitarDay.com did an excellent post on this: