I have a Mid-2010 MB and on Monday of this week I got a service battery warning. At the same time my L shaped charger stopped working, so I bought a new one so I could at least maintain a charge till I could get my battery fixed. However, the new L shaped charger didn't work. I figured this was obviously a battery issue so I ordered a new battery from Ifixit and figured I'd need to wait till the battery was replaced. While my sister was over, I figured I would try using her T-shaped charger from her Mid-2009 Mac Book pro and Voila! it charged. I just changed my battery, and while the service battery light is gone and I've got a working battery, my computer still will not charge from the L-shaped mag safe. However, my sisters T-shaped charger is working just fine. I'm not sure what to do, I'm considering ordering an old T-shaped charger, but since I just bought a new charger I'm a bit hesitant to do so until I've exhausted all my options with the L chargers. Any advice or input would be very welcomed as I can't keep my sisters charger forever.