For some reason, my Windows 7 (Ultimate, 64bit) laptop will not power off the display and keep it off if I have the screen saver and/or the timed auto-lock enabled. Either the display blanks (and locks) but never powers off, or it powers off for less then a minute, then the back light visibly powers back on and stays on, even though the screen remains blanked until I touch a key or the trackpad.
I’ve tried varying the screen power down time to greater than, less than, and exactly equal to the blank screen/lock time, with no success.
Turning the screen saver and the timed auto-lock off does allow the timed display power down in the power settings to work properly.
(Note that I am not talking about system sleep or hibernate. I’m talking about when the machine remains running, but only the display should power down.)
After periodically searching for solutions to my problem for a few weeks I finally found out that this problem is rare but not unique to my system. As far as I can tell there’s no actual fix, but the workaround is to switch from the “(None)” or “Blank” options in the screen saver menu to another one, such as Ribbons.
This is suboptimal, since I don’t really want any sort of visual screen saver, but setting the screen saver timeout to one minute below the screen power off timeout is tolerable.