About a week ago, I was working on a MacBook Pro with a dying hard drive. I was able to access the drive via Firewire Target Disk in order to repair the drive using Disk Warrior. The whole process was expected to take at least five hours.
While in the past I’d always just left the LCD display open, in this case I accidently closed the lid. Shiz, I thought! I’ve just waisted the last few hours of hard drive repair; but when I check Disk Warrior, I noticed it was still working perfectly!
I tried opening and closing the display a few more times, the MacBook Pro kept running with the display closed. I just tested closing the lid on my Powerbook G4 – it worked too! I can only assume that all Mac displays can be shut when in Firewire Target Disk Mode — only wish I would have learned this years ago.