I sold a friend a MacBook core2duo. He was going to give his grandson, a budding film maker. A few weeks later he brought it back saying there was no power. I tried a power cord i knew to be good on his machine, no led light up. I had a couple of spear parts units, so I decided to swap out the mag-safe socket.
I followed the guide on ifixit.com it was easy peasy. I harvested the part from the spare parts machine, and yanked out the defective part from my friends unit. I installed the working mag-safe port and reassembled the MacBook. The moment of truth, I plugged in the power cord and the led lit up, success! My friend thinks I'm a computer genius, thank you ifixit.com, and his grandson gets to continue making videos on the MacBook grandpa gave him for his birthday.
I have cracked open the MacBook a few times, and I just have to say how much easier it was using the Magnetic Mat. All those little screws are easily dropped and misplaced and the dry-erase surface lets you make notes about what went were.