Answer to "MacBook only boots fully occasionally, otherwise black screen"Hi. I had the same problem on a A1181. I just removed the hard drive and then booted from a Snow Leopard USB bootable Stick. Since the screen turned on, it seemed it was a hard drive issue. So I Installed that hard disk on another Macbook, which didn't boot. Finally, I solved it by installing a new hard drive on it and just worked. Hope it work for you. Good luck!