My partners MacBook hasn't been booting not sure of the cause she gave it to someone to repair the screen and they messed up. i just get the flashing folder and ?. I've tried entering recovery to no avail . I have burnt tiger dmg which it was running and tried to boot from disk, I just got grey screen and it ejected the disk and then tried to enter start-up manager I then get a grey screen with a mouse pointer that I can track with the pad but nothing else even after leaving for an hour or so. Any help would be great.