Hey all, new here.

I know that without seeing the guitar in question, it may be a bit tough, but I'm hoping somebody's seen this before.

A friend's J-45 has develop and odd S-curve in the neck. Looking down the neck, it rises till about the twelfth fret, then falls off. It looks like an "S" viewed from the side looking down toward the headstock. The guitar sound not bad doing regular chording, but anything around the 12th fret or higher is unplayable.

Is this thing screwed? Is it a truss adjustment issue?
Well, most acoustic guitars fretboards will fall off after the neck meets the body. The other part sounds like the neck has some back bow.

I'd adjust the truss rod until the back bow comes out and ignore the fall off where the neck meets the body.
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