My iBook will not display anything on its screen. Rather, it just remains black. One time, the screen did come on, but then shortly after booting, it flickered a lot and then went black again. A year ago, something similiar happened and when I took it to be serviced (when I had AppleCare), they had to send it away and have a new logic board installed. Now this machine is out of warrenty and and I am not sure what to do, or even if it is the same problem. Any suggestions?? Thanks!