Occasionally when I open the lid of my Lenovo ThinkPad T500 laptop, I get a blank screen – nothing at all is visible on the laptop’s display, even though the machine is powered on. In particular, this tends to happen after I undock the computer from the docking station, close the lid, wait a short time (i.e. carry the laptop with the lid closed into another room), and then open the lid again.
I’m not sure what the root cause of this issue is. However, I’ve found a workaround to get the display to come back on after I’ve opened the lid and the display is blank: Press Fn+F7. (This is the same keystroke that switches display modes when multiple monitors, or a projector, are connected to the PC.)
(Note: I don’t have the Lenovo Presentation Director application installed on my machine, because it doesn’t seem to work very well with the 3-monitor configuration I have at my desk. Presentation Director overrides the Fn+F7 keystroke; thus, I’m not sure whether this workaround would work on machines with Presentation Director installed.)