I don't know a lot about the internals of iMacs, but I had a question... I took my Late 2012 iMac into Apple Store for repair as I had lines on my monitor (not like the ones you can google, like grid lines/guide lines that you'd see in Illustrator/Photoshop and it turned out I had to have the screen replaced. Today I was noticing that my audio output and computer speakers and putting crackles/spaces/mistakes in my audio (I can't even describe it)... I tried my speakers, my headphones and I even get them on Bluetooth. Could my audio have been damaged during this repair or would this be a completely separate issue? Any advice would be appreciated.