My Laptop (a Inspiron 17R N7110 running a 64-bit Windows 7 has been making a buzzing or grinding noise (for lack of a better term) coming from the upper left corner.  There is also a slight vibration on the left side.  This happens whenever the computer s running, so it's not an audio issue.  Is this a problem with  the cooling system, or something else?  How do I fix this?