Newbie1770

So when you say fine tuning is done at the bridge - is that done with the round things at the end of the strings on the body? Sorry - a very new newbie here.

I just bought a JTV-89F and she is beautiful but she sounds like death - completely out of tune. I did not know about the locking nuts and tried to tune the strings manually by turning the tuning knobs, which caused no change. Now, I have researched and found that those nuts are for auto-tuning. I'm certain that all of my adjusting has made matters worse. Can I loosen the nuts and tune it manually to get it back on track or did I break this thing? Thank you in advance.