My boyfriend just bought an used MacBook and when he tried to upgrade it to Leopard, it blacked out during installation. First we thought it was just the display going to sleep, but it did not respond to anything we did. It was weird, because only the DVD unit and the hard drive turned off, but other fans were still running. We tried to reset it while the battery was out and changing the RAM but it didn't help. Any ideas what could be causing the problem? Thanks.