My mid 2011 MBP has been running off of the cord since July. The battery is dead and holds 152 Mah compared to the original 5700 or so. It has been working fine since I turned it off yesterday. Today I went to turn it on and I get a small loading bar at the bottom followed by a small grey spinning wheel. About 8 seconds after the computer turns off. Any suggestions on what I could try to get it working other than taking it in.