Currently Being ModeratedNov 25, 2012 4:35 PM (in response to Micahel)
it's putting the monitor as second display, so the login screen (i'm guessing) is only displaying on the first—main—screen, the the one that is cracked.
restart the macbook and don't touch anything. when the background appears on the secondary monitor, you know the login screen must be up on the first monitor. so type in your username, hit TAB once, then your password.
you should be able to log in now. then follow these instructions:
(bare in mind i'm running 10.6.8)
1) press ALT+F2 to open up displays in system preferences.
2) you should be able to see a dialog open up in the secondary monitor
3) if this has a "Gather Windows" button, press it
4) if step 3) works, you should be able to switch around the main displays, or turn on mirror mode, or whatever