So yesterday I dropped off my MacBook Pro (Early 2011) at the Genius Bar for an issue with my hard drive seeming to corrupt itself. I left it overnight and they found nothing. However, the Genius Bar replaced the Logic Board to make sure it wasn't a processing issue either with the CPU or GPU that was causing my issue. Now that I am home (worked all day and just got the chance to use my computer now), I went into iTunes and decided to listen to some music. However, now I am not getting sound out of my left speaker. iTunes shows that there should be sound, and with headphones it is fine. Everything was working perfectly before I brought it to the store for repair. Is there any quick fix or should I go back to repair this issue? I have AppleCare until 2014 so coverage isn't an issue. That, and they didn't "burn" my Serial Number into this new board so I'd have to go back to the store anyway. Thanks for any advice!