Upgrade logic board of Macbook Unibody 4.1
I have received my new logic board today and installed it successfully. I also upgraded the Macbook with a 240GB SSD and 4GBs of RAM.

I only encountered 2 problems which can be worked around easily. The first one was the different SuperDrive connector. I simply didn't connect the SuperDrive, but you can easily order the right SuperDrive, since they're not that expensive. The second and most important problem I encountered was the different layout of the heat sink. This needs replacement as well in order to get it working properly. I'm still waiting for this part to be delivered. For now, my Macbook shuts down after a few minutes, because it gets too hot.

After I've received the right heat sink and installed Yosemite, I'll give you guys another update.