The action on your guitar is high and you take it to your technician to correct it. If he says it is a two-minute job, and picks up the hex key (Allen wrench), stop him then and there.
By picking up the hex key, what he intended to do, most probably, was to work the truss rod one way or the other. The truss rod is an iron rod with a hex nut on one end and sits in a groove in the neck, right under your fretboard/fingerboard. It can be accessed either through the soundhole, or from the headstock end.
The purpose of the truss rod – in any guitar – is to dial in the right amount of relief (the string-to-fretwire gap) in the neck. IT IS NOT A PROCESS TO CORRECT ACTION, no matter what your tech or anyone else says.
The right way to correct action on your instrument is a three-step process, correcting
a) action at the 12th fret (adjusting saddle height)
b) action at the 1st fret (adjusting the string slots in the nut), and
c) dialling in the right amount of relief in the neck.
I will discuss these in the next post with a set-up undertaken on a customer’s guitar.