The infamous fret buzz is a symptom of many possible problems. While most fret buzz issues can be solved by a simple and routine Guitar Setup, in many cases the cause of fret buzz is simply that the player is playing too hard. Even a perfectly setup guitar, if played too hard, will have fret buzzing.
Other causes of fret buzz could relate to any of the following issues: uneven frets, improperly adjusted truss rod, bridge saddles loose, or nut over-worn. Please refer to the following articles for more information on how to correct these:
Adjusting the Truss Rod
Can I modify the clear polymer nut? The slot heights needs adjusting.
How do different string gauges affect my playing?
How do I properly care for the Fretlight Guitar?
How does weather affect my guitar and how can I adjust for it?
I think my pickups are too high/too low, how do I adjust them?
I thought I could adjust the bridge saddles myself but now the guitar plays worse than ever, what did I do wrong?
I’m having issues with the small bridge saddle screws being loose and making a rattling noise, how can I fix that?
My Fretlight needs some adjustment. What are the proper setup/adjustments for the FG-400?