Hey there,
I have a problem with my truss rod. I wanted to tighten up the neck to eliminate some buzzing on the first frets, but... none of the wrenches I used, fit in the truss rod. I've used all sizes of allen wrenches, various screwdrivers, and still nothing. Tried going both ways. Then I decided to look inside and found out that there's a screw thread in there. And also a place for a flat-blade screwdriver, but it wont move. Wat do?

The guitar is a custom made Ran from 2002.

Best pic I could take:

Born to lose, live to win.