About half the time when I switch users or resume from standby or resume the screen goes blank (black). If I work the cursor keys I can hear the system bell when it gets to the end of the user list. I can also successfully login, going from memory, but screen stays black. Sometimes closing and re-opening the lid will light up the screen again. Pressing the special Function key to enable/disable external monitor connection has no effect [Fn]-[F5],[Fn]-[F6]. If none of the previous work I need to put the computer into hibernation or full power off to restore screen function.
If I watch closely when switching users I think I can see the screen initially start to light up and then quickly fade to black.
The computer is an Acer Aspire 3500, model ZL6, running Ubuntu 10.10 installed 2 days ago. No proprietary drivers are in use. I'll provide a list of hardware details as soon as I can figure out how to generate that (didn't there used to be an entry for hardware details under the System menu?).
Possibly related questions:
- No resume after Hibernate or Standby
- When I resume from suspension - the screen is blank
- Switch user fails to complete successfully
For what it's worth, blank after resume also used to happen occasionally when the laptop was running XP-Home, but nowhere near as often, perhaps 6 or 8 times a year.
UPDATE: I found System > Administration > System Testing and ran the Monitor test. It went very very dark, but the window elements could be discerned, and the whole screen flashed (from very very dark to black). On the third repeat of that same test the screen went to full blaupck and stayed there. Moving the mouse, via touchpad, or touch keys did not wake it up again. I had to close the lid and put the computer into hibernate, and press the power button to restore it.
UPDATE2: output of lshw: http://pastebin.com/q7n8676r, lspci: http://pastebin.com/6ujzVK4r
UPDATE3: sometimes I can restore the screen by flipping to console 1 with ctrl-alt-F1 and then back to graphical with ctrl-alt-F7.
This reminds me of a fixed Lucid bug (LP #546578) when x-server gamma was not restored properly from resuming gnome-screensaver. The solution there was to disable gnome-screensaver until the bug was fixed, which is probably not a good idea on your laptop. The underlying bug in X-Server may not yet have been fixed - I haven't followed that. You could check if it's related to this by typing
in a terminal to see if the display gets bright again.