I got my Ibanez s470 set up professionally last year, it has stayed in tune really well - I just have to adjust the screws on the saddle a little every once a while.

The other day it went out of tune and I tried to tune it - I was not able to get the B string back in tune no matter how much I adjusted the saddle screw for this string. The highest it will go up to is A. Should I take the guitar back to the shop to have this fixed or can I just buy an allen wrench and adjust the intonation of the string myself? All the other strings seem ok, but I'm worried I'll mess up the intonation of the rest of the strings if I try to adjust this one string. I'm still pretty much a noob when it comes to floyd rose guitars. THanks.
use the machine heads
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Quote by vegetable-jim
use the machine heads

After loosening the locking nuts.
Yep, just unlock the nut and then retune using the machine heads, make sure to stretch and bend the string first before finally retuning and locking the nut, making any fine tunings with the fine tuners (:/)
Schecter C-1 Hellraiser FR <3
Unlock the nut and tune with the machine heads. And then if and when it goes out of tune a little bit again just use the fine tuners.