Hey, I'm trying to fix my friends Macbook Pro. Everytime it's turned on it stays at the grey screen and does not go any further than that. The Apple logo on the gray screen doesn't even show up. She says she didnt hit it up against anything or spill anything in it. It seems the hard drive makes a clicking noise for the first 30 seconds or so, but eventually stops. I've tried to get it into single user mode, but that won't even work. Any suggestions?