Difficulty With Tuning My Guitar

Forgive me for the noob question, but I just got my first guitar, a used Ibanez RG5EX1, and I'm having trouble with tuning it. I brought it to Guitar Center to have a setup and get it re-strung, but when I turn the knobs to tune it, nothing changes. It doesn't matter how many times I turn the knob, the pitch/tone doesn't change whatsoever. I keep hearing the term Floyd Rose associated with my guitar and i don't know if that has any thing to do with my problem, but any help would be greatly appreciated.