Blank screen after Switch User or Resume

Question

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.

Solution

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

xgamma -gamma 1.0

in a terminal to see if the display gets bright again.

Comments

[Jason Southwell]

what is the output of lshw and lspci? need some information about the graphics hardware. the logs from when your system returns from this problem would also be helpful (if you know where they are, if you don't, then no need to stress over them. additionally from the fact that xp also had this problem, sounds like faulty hardware. have you had this system checked?

[matt wilkie]

lshw & lspci links added; have I had the system checked? well I've run diagnostics for memory and hard drive (ubuntu boot cd, sysrescue cd). Other than that I've no idea how to get it checked. All of the local computer repair outfits I've dealt with think the way to solve problems is to nuke & pave (or buy a new system).

[matt wilkie]

conducting the monitor power saving test seems to be a reliable means of causing the problem, though the number of times it takes to black out and not return is inconsistent (range of 3 to 10 times).

[topless]

I had similar problems that i solved by moving to kernel version 2.6.36, you can check my relevant question askubuntu.com/questions/25208/…. For your version in a terminal run: uname -a

[Christoph Jüngling]

(Sorry, I can't post comments yet, so it has to be an answer, though it isn't.) I have a similar problem on Ubuntu 11.10 64bit: The first switch to another user is always possible without any problem, and after logout of this one the user list is displayed and I can login as usual. Then, after confirming the password of the still logged in user, the screen runs completely black with the white mouse pointer beeing moved according to my mouse movements. Ctrl+Alt+F6, login, then sudo shutdown -r now works, and after reboot all things are fine.