Capo on first fret, press down 17th fret, measure neck relief on E and G sides at 7th fret with feeler guage .
Set truss rods for 10 thou on G and 12 thou on E... ??
loosen both truss rods and check relief increases - therefore truss rods are working
re-tighten truss rods to get the 10/12 thou relief - if there are still free turns on the truss rods (ideally enough to get some back-bow) then all is AOK.