Respuesta a "MacBook doesn't power up"Hi had the same problem, mine will not run with 2 ram sticks installed but it did boot with just one in the 0 slot. It was working with 1 gb ram installed but not 2. Good luck
Respuesta a "MacBook Core Duo not working properly after internals were replaced"I have 2006 core duo I just bought from a gal very cheap. She was told by Apple genius that logic board was faulty and had to be replaced. I removed the board and gave it a good cleaning and inspection with magnifying glass. I didn't see any hot spots, ie discolored solder. So I put back in and still had same problems as you until I played with switching ram around. I found I have a bad ram slot but a 1 gb stick works great in slot 1. Now it boots and runs fine as long as I leave slot 0 empty. Good luck Update: Okay I also bought a newer MacBook 5,2 made in early 2009 I got a good deal because the keyboard didn't function correctly. I ordered a used replacement version 3 top case for that one and all has worked perfect since. Just be sure you get the correct version.