Diagnosing a broken laptop I have a 12" PowerBook with no HD and a dead screen. I'm trying to determine if the actual LCD is broken or if it is "just" the graphics card, without taking out the screen and transfering it to another computer (which I intend to do if the screen is working). I've tried connecting the computer to an external monitor, but, since there is no HD, nothing happens. The same nothing happens when I connect my working 12" PowerBook to the external monitor.

Is there a secret keyboard combination that tells the laptop to throw some characters onto the screen (from BIOS or something), and to mirror or output to the external monitor?
No. Just get a small, cheap HD (even just a 20 GB will do fine here), put it in, and boot from a system installation disk as if you were going to install the OS.