Hi! After much fiddling around with the truss rod and saddles, I finally got my Aerodyne Jazz Bass to sound and play OK. Tuning and intonation are good, and action is acceptable. However, frets 4-6 on the G string are dead. It's almost like they're being muted when played, and although the note rings, it's a dull thud with no sustain. Unfortunately, there are no luthiers in my area, so it's a do-it-yourself scenario. It still has the original strings. Could this be the problem? It's only those three frets on the G string that are an issue, which leads me to believe it's not the strings. Any help appreciated!