My battery won’t charge and the light doesn’t come on

A light green MagSafe LED is telling us the switching MOSFET on the logic board is leaking. This happens when a cheap knockoff charger was used damaging the logic board.

Here’s the IFIXIT guide you’ll need to follow to replace it MacBook Pro 15" Unibody Mid 2009 Logic Board Replacement and here are the possible logic boards MacBook Pro 15" Unibody (Mid 2009) 2.66 GHz Logic Board, MacBook Pro 15" Unibody (Mid 2009) 2.8 GHz Logic Board or MacBook Pro 15" Unibody (Mid 2009) 3.06 GHz Logic Board. While someone with good skills could diagnose the logic board and repair it the cost is not much more to just replacing it.

You still have an issue with the battery and charger. You’ll need to get a real Apple charger to replace yours. Lacking safety features, cheap MacBook chargers create big sparks & Counterfeit Macbook charger teardown: convincing outside but dangerous inside. You also want to use a good surge suppressor as well.

Once you get your system working check the batteries health using CoconutBattery paste a snapshot of the main window here for us to see 在已经存在的问题里加入图片