I turned on my MacBook Pro yesterday after being in Windows, when I pressed the power button the display didn't turn on. I thought this would be a minor problem, so I forced it to shut down, then started it up again. to no avail. I can hear all the internal stuff working (hard disk etc.) so I don't think it is a problem with that. I also tried to plug in an external display (this display had previously been set up as the main display) and it wouldn't show a picture. I think it is worth noting that after leaving it alone for a while (with no power) the display did work, as did the external display, but after sleeping it for the night there is again no display. I desperately need it working and any help would be appreciated.