Hi guys, I have just run into a problem while restringing my Gibson Buckethead LP. One of the locking Grover rotomatic tuners is having an issue where the locking cam (which secures the string inside the post) is not opening, and opening or closing the thumbwheel has no effect. There is no string caught in there, but it means I am now unable to lower the cam insert to put a string in there. I've tried every variation of winding/unwinding the thumbwheel to no avail. Super annoying and I have no idea how to try and fix this?!! Has anyone run into this before and have a clever idea? Cheers, Simon.