My friend gave me his laptop thinking that his hard drive crashed. After replacing the hard drive still the same issue. (Wouldn't boot) I asked him what had happened. He told me that he had it sitting on his coffee table and his kids ran past it and knocked it off. I tried to put a windows cd in and the CD drive just made a noise. It would not read it at all. At this point I decided to try a USB drive with a Windows install on it. That didn't work either, just sat at a black screen. I'm wondering if the problem would be the motherboard or the CD drive. Does anybody have any insight on how to narrow this down to which component could be broken? 