earlier this summer when i was playing a gig, i used the whammy bar really fast and the "A" string went way out of tune. i figured i broke a string so i bought new strings. i was stringing the "A" string and the "ball" end of the string wouldnt fit where it was sopposed to go, the hole seemed to close up or something. i put the string in backwards so it would fit but the fine-tune knob wont turn. can anyone help??