Sorry if this has been covered, I don't know enough vocabulary about these technical things to do a successful search on the subject... I just got this epiphone thunderbird today. I love it so far... I was changing the strings and doing a setup. I had taken the strings off to get to the truss rod cover. When I was all finished, I started winding up the strings. Everything did fine... except when I got to the D string, it got really hard to tune. I got it up to tune, but then it made a noise and went way out of tune. The actual tuning head itself won't stay on now. I can put it on and tune it, but nothing is really holding it on, so it falls off if I take my hand off of it. Any idea of what this might be? On the back of the machines, most of them are flush, but this one has a metal piece that isn't flush. I can push it up and make it flush, but it comes back out too. Is it broken? Do I need to describe it better? Thanks... this is just kind of a bummer to deal with. If it is broken, I guess I can just take it back to GC.