Advertisements

Rebooting a Dell U2711 Monitor

It turns out my fancy Dell U2711 landscape monitor doesn’t work well with Displayport video. I normally leave it in power-save mode, with the power LED slowly fading orange, but about once a week it won’t start up when I turn on the PC. It seems the only solution is a hard power cycle, so I plugged it into a remotely switched outlet to eliminate having to pull its plug.

Now that I know what to watch for, it’s easy to work around: if the power LED doesn’t turn blue when the PC power goes on, immediately turn off the PC power and power-cycle the U2711. If I let the PC continue in Xubuntu, the U2713 portrait monitor becomes the primary display and X helpfully rearranges the video configuration around the disabled U2711 until I manually un-wedge things. If I shut down the PC while it’s still displaying the BIOS intro screen, then click-click the remote power switch, the U2711 will be good for another week or so.

Every month or so, the U2711 won’t light up after going into power-save mode, even though the PC is still running just fine. I set Lightlocker (which replaces the classic screensaver on Xubuntu) to blank the screen after 10 minutes and turn off the display power after 11 minutes. When the U2711 doesn’t light up, some delicate xrandr surgery through the U2713 will bring the U2711 back to life.

The starting situation looks like this:

xrandr
Screen 0: minimum 8 x 8, current 1440 x 2560, maximum 16384 x 16384
DP-0 disconnected primary (normal left inverted right x axis y axis)
DP-1 disconnected (normal left inverted right x axis y axis)
DP-2 connected (normal left inverted right x axis y axis)
   2560x1440      60.0 +
   1920x1200      59.9  
   1920x1080      60.0     59.9     50.0     24.0     60.1     60.0     50.0  
   1680x1050      60.0  
   1600x1200      60.0  
   1280x1024      75.0     60.0  
   1280x800       59.8  
   1280x720       60.0     59.9     50.0  
   1152x864       75.0  
   1024x768       75.0     60.0  
   800x600        75.0     60.3  
   720x576        50.0     50.1  
   720x480        59.9     60.1  
   640x480        75.0     59.9     59.9  
DP-3 connected 1440x2560+0+0 left (normal left inverted right x axis y axis) 597mm x 336mm
   2560x1440      60.0*+
   1920x1200      59.9  
   1920x1080      60.0     59.9     50.0     24.0     60.1     60.0     50.0  
   1680x1050      60.0  
   1600x1200      60.0  
   1280x1024      75.0     60.0  
   1280x800       59.8  
   1280x720       60.0     59.9     50.0  
   1152x864       75.0  
   1024x768       75.0     60.0  
   800x600        75.0     60.3  
   720x576        50.0     50.1  
   720x480        59.9     60.1  
   640x480        75.0     59.9     59.9

Note that there’s no asterisk on DP-2’s 2650x1440 entry, which means it’s not active. In fact, it’s jammed in power-save mode and nothing other than a hard power cycle will wake it up.

The U2713 portrait monitor wakes up just fine, so X piles all the program windows into an untidy heap on that display, but, with enough Alt-Tab action, I can eventually resurface the console window and start typing:

xrandr --output DP-2 --off
xrandr --output DP-2 --auto
xrandr --output DP-3 --right-of DP-2

The DP-2 and DP-3 outputs correspond to what xrandr reported above.

Then I must rearrange all the windows on both monitors again, but that’s much easier than the hocus-pocus required to recover after rebooting the PC with the U2711 shut down.

The normal (or recovered) video situation looks like this:

xrandr
Screen 0: minimum 8 x 8, current 4000 x 2560, maximum 16384 x 16384
DP-0 disconnected primary (normal left inverted right x axis y axis)
DP-1 disconnected (normal left inverted right x axis y axis)
DP-2 connected 2560x1440+0+0 (normal left inverted right x axis y axis) 597mm x 336mm
   2560x1440      60.0*+
   1920x1200      59.9  
   1920x1080      60.0     59.9     50.0     24.0     60.1     60.0     50.0  
   1680x1050      60.0  
   1600x1200      60.0  
   1280x1024      75.0     60.0  
   1280x800       59.8  
   1280x720       60.0     59.9     50.0  
   1152x864       75.0  
   1024x768       75.0     60.0  
   800x600        75.0     60.3  
   720x576        50.0     50.1  
   720x480        59.9     60.1  
   640x480        75.0     59.9     59.9  
DP-3 connected 1440x2560+2560+0 left (normal left inverted right x axis y axis) 597mm x 336mm
   2560x1440      60.0*+
   1920x1200      59.9  
   1920x1080      60.0     59.9     50.0     24.0     60.1     60.0     50.0  
   1680x1050      60.0  
   1600x1200      60.0  
   1280x1024      75.0     60.0  
   1280x800       59.8  
   1280x720       60.0     59.9     50.0  
   1152x864       75.0  
   1024x768       75.0     60.0  
   800x600        75.0     60.3  
   720x576        50.0     50.1  
   720x480        59.9     60.1  
   640x480        75.0     59.9     59.9

Note that DP-2 now sports an asterisk.

The width of Screen 0 covers the U2711 in landscape and the U2713 in portrait: 4000 = 2560+1440. The height comes from the U2713 in portrait mode: 2560.

That this should not be necessary goes without saying. The U2711 run with firmware revision A09, which was supposed to fix the problem, but Dell basically walked away from it.

I’m pretty much forced to use Displayport video for both monitors, as a low-profile nVidia card with two dual-link DVI-D outputs doesn’t seem to exist. The Dell Optiplex 980 disables the system board video when it finds a PCI-E video card, so there’s no way to run the U2713 from the system board Displayport and the U2711 from a dual-link DVI PCI-E video card.

Advertisements

  1. #1 by tantris on 2015-05-06 - 09:44

    There probably is a way of sending some I2C data to the monitor’s vga port once in a while.
    But I assume, you would need an arduino some sugru and a laser cut plywood box…

    • #2 by Ed on 2015-05-06 - 09:46

      And, surely, a 3D printed bracket…

      • #3 by tantris on 2015-05-06 - 20:46

        An interesting site:
        http://flipthatbit.net/2011/04/interfacing-i2c-the-easy-way/
        Of course your problem is at the other end. And I guess, sending clock data to the vga port while you are using the monitor, would possibly switch it to the other input.

        • #4 by Ed on 2015-05-07 - 07:36

          That’s … heroic …

  2. #5 by Joel on 2015-05-06 - 10:28

    Have you tried a displayport -> hdmi adapter for the U2711? Maybe the hdmi input is better behaved?

    • #6 by Ed on 2015-05-06 - 11:45

      a displayport -> hdmi adapter

      The HDMI input works fine, but limits the display to 1920×1080 dots: not nearly enough!

      There’s apparently a newer bigger better faster HDMI standard that goes to 2560×1440, which the U2711 doesn’t have.

      I also tried a DisplayPort to Dual-Link DVI adapter that didn’t work any better.

      [mutter]

      • #7 by Joel on 2015-05-06 - 13:04

        I’m gonna guess that you’ve tried tracking down the actual manufacturer of the monitor to see if they have a firmware fix? Or maybe a bios fix that doesn’t disable the onboard video?

        • #8 by Ed on 2015-05-06 - 14:41

          My level of Google-fu showed that none of the many folks kvetching on the forums had gotten anywhere and that none of the increasingly desperate half-assed fixes worked, so I just gave up and bought the remote power switch, which does work when the U2711 fails to start up.

          As nearly as anybody can tell, a hardware oversight inside the monitor doesn’t properly convey Displayport status to the firmware, so it seems to require more than a firmware fix. The U2713 monitor works fine and, in fact, lights up as the primary monitor while the U2711 snoozes on, so Dell got it right after a while.

          The U2711 worked perfectly through dual-link DVI with the 2005FPW (through VGA) as the portrait monitor, up until the 2005FPW died and I “upgraded” the whole setup. Seemed like a good idea at the time, is all I can say…

  3. #9 by Raj on 2015-05-07 - 03:02

    I had a similar problem with a 24″ Dell monitor with touch buttons. After a week of power down the monitor wont power up the first time. I had to plug the power cord out and wait 10 mins and try again – mostly worked. One day a black line started down the center and got worse and out it went! The new model had a tactile power On button with not such problems.

    • #10 by Ed on 2015-05-07 - 07:39

      The U2711 has field-sensing non-contact buttons that wake up when I reach for doodads stashed under that corner of the monitor. Eliminating four mechnical switches probably seemed like a good idea at the time, but the U2713 has four mechanical switches.

  4. #11 by Mike on 2015-05-07 - 12:29

    So save the hassles and sell the still-good 2711 on ebay and buy a second 2713 That gives you identical monitors, which can be a useful option when one dies. A quick look on ebay says that a good used 2713 is anywhere from $10 to $75 or so more than a good used 2711.

    • #12 by Ed on 2015-05-07 - 13:11

      The U2711 has gorgeous screen color, better than the U2713, an SD reader slot that gets surprisingly heavy use, and, part from occasionally waking up dead, seems just about perfect…

      Some day I’ll run it from the DVI input and it’ll be all good again. [sigh]