So about a month ago I sent my 360 in to get repairs. I recently got it back the other day, only to find that they sent me a "replacement unit", which I thought; awesome, it's completely new, no problems.

Why was I wrong?

It seems to run fine; if I were deaf. Whenever I insert a 360 game into the console, it makes a terribly unhealthy grinding noise. There's no damage to the game itself, and I don't wanna crack the warranty by opening it and seeing what's going on for myself.

I can't even register for a repair on the website anymore, because apparently it's still being repaired.