I picked up a for parts PowerBook G4 the other day. It seems mostly complete minus the top case and the screws needed for the top case. I was wondering if there was a way to boot the machine without the top case? I ask because I want make sure the machine boots up and works OK before I go out and buy a top case. Its the last model of the 15" PowerBook G4, A1138 DL SD Hi-Res 1.67GHz. Thanks!