So I bought a iphone 4s from a close friend. I only paid $50 and i was in a pinch since my droid took a dump. There is a small crack in the top right corner of the screen and the mic doesnt work for anything. It only works for speakerphone. Siri doesnt work, voice memos dont work. Does it void the warranty if the screen is cracked but the problem is the microphone? The warranty expires june 24th 2013.