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I just replaced the logic board in my late 2011 a1278 Macbook Pro Unibody. It was diagnosed dead by apple so I thought I could replace it myself. So I put it in and it would not turn on. Just shows a dim green light on the charger. I bought the logic board for 250$ off Ebay from a good seller. The board doesn’t get warm at all even after charging for 4 hours so I don’t think it is getting power. Please help me!
A dim MagSafe LED often points to a bad charging logic on the main logic board. So I’m suspecting the replacement board you got is likewise damaged as well. You still should check the DC-In board for damage. Here’s the IFIXIT guide to get to it: MacBook Pro 13" Unibody Late 2011 MagSafe DC-In Board Replacement and heres the replacement part if you need it MacBook Pro Unibody 13" and 15" MagSafe DC-In Board. Make sure the small SMT components are not missing or damaged on the logic board.