How to fix dead keys?
Several keys are dead: <left cmd>, plus <c> through <m>, <,>, and <.>. Is there a repair guide for the keyboard itself? How about replacement parts?
Released October 24, 2011 / 2.2, 2.4, or 2.5 GHz Quad-core Intel Core i7 Processor
Sounds like you have had a short. The keyboard will need to be replaced. The part can be found on eBay usual about $25-$40. Make sure you get the one for your machine and with a back light (a little more). The cable that connects to the logic board is slightly different on some machines. It will take you a while to remove the approximately 85 tiny screws and put them back in. I use an electric screwdriver to remove them. The job takes me about 1 1/2 hrs to 2 hrs. to complete but I've done it a lot. Add an extra hour and try not to be disturbed. Here a guide for the 2010 machine but is the same for your 2011: MacBook Pro 13" Unibody 中期 2010 键盘更换