External Monitor Issue – Monitor Turns Off Every 5-10 Minutes

16.04multiple-monitorsthinkpadxrandr

I'm using Ubuntu 16.04 installed on Lenovo ThinkPad T500 laptop with two external monitors connected via display and VGA ports.

I think the issue started after I upgraded to Ubuntu 16.04. But I'm not sure about this.

Occasionally at some random moment one of the monitors turns off. It looks like there is no signal on the monitor. In 2-5 seconds the monitor turns on. This might happen several times in a row with small delays or might not happen for a long time. Both monitors might turn off at the same time or one by one.

I do not understand why this happens. Either I do not understand what should I do to reproduce the issue. Last time (a moment before I wrote this) this happened when I switch to a different tab in Google Chrome and pause YouTube music video. But when I try to do the same one more time the issue is not reproduced. I kept using the computer all the time looking at the screen and writing this question at the moment when issue happened

I failed to find any signs of the issue in the logs.

My issue looks close to Monitor turning off randomly Ubuntu 13.10 with the differences that only one monitor might turn off instead of two and they turn on automatically.

By coincidence I've entered the command xset -q and pressed enter key right at the moment when the monitor turned off. I waited for several seconds and saw the result

$ xset -q
Keyboard Control:
  auto repeat:  on    key click percent:  0    LED mask:  00000000
  XKB indicators:
    00: Caps Lock:   off    01: Num Lock:    off    02: Scroll Lock: off
    03: Compose:     off    04: Kana:        off    05: Sleep:       off
    06: Suspend:     off    07: Mute:        off    08: Misc:        off
    09: Mail:        off    10: Charging:    off    11: Shift Lock:  off
    12: Group 2:     off    13: Mouse Keys:  off
  auto repeat delay:  500    repeat rate:  33
  auto repeating keys:  00ffffffdffffbbf
                        fadfffefffedffff
                        9fffffffffffffff
                        fff7ffffffffffff
  bell percent:  50    bell pitch:  400    bell duration:  100
Pointer Control:
  acceleration:  5/1    threshold:  5
Screen Saver:
  prefer blanking:  yes    allow exposures:  yes
  timeout:  0    cycle:  0
Colors:
  default colormap:  0x22    BlackPixel:  0x0    WhitePixel:  0xffffff
Font Path:
  /usr/share/fonts/X11/misc,/usr/share/fonts/X11/Type1,built-ins
DPMS (Energy Star):
  Standby: 0    Suspend: 0    Off: 0
  DPMS is Enabled
  Monitor is On

What can I do to investigate the issue? What log files should I check? I failed to find any signs of the issue anywhere in the system.

Is this a known issue? I might describe it wrong when searching for it and thus failed to find it.

How can I understand if it is a hardware or software issue? I might install Windows and see if the issue happens with Windows or not. But may be there might be an option to check this using Ubuntu.

What can I do to prevent the issue?

Update:

Following suggestion in the answer I tried to do the following to reduce the refresh rate on my screens. I had a refresh rate 59.95 Hz and decided to change it to 58 Hz.

Identify existing refresh rate

xrandr -q

Created parameters for the new mode

$ cvt 1920 1200 58

\# 1920x1200 57.93 Hz (CVT) hsync: 72.01 kHz; pclk: 185.50 MHz
Modeline "1920x1200_58.00"  185.50  1920 2048 2248 2576  1200 1203 1209 1243 -hsync +vsync

Registered new mode

$ xrandr --newmode "1920x1200_58.00"  185.50  1920 2048 2248 2576  1200 1203 1209 1243 -hsync +vsync

Added this new mode to both screens

$ xrandr --addmode DP1 1920x1200_58.00
$ xrandr --addmode DP2 1920x1200_58.00

Selected this newly added mode for both screens

$ xrandr --output DP1 --mode 1920x1200_58.00
$ xrandr --output DP2 --mode 1920x1200_58.00

As a result now xrandr -q shows the following output

$ xrandr --query
Screen 0: minimum 8 x 8, current 3840 x 1248, maximum 32767 x 32767
eDP1 connected (normal left inverted right x axis y axis)
   1920x1080     60.00 +  59.93  
   1680x1050     59.95    59.88  
   1600x1024     60.17  
   1400x1050     59.98  
   1600x900      60.00  
   1280x1024     60.02  
   1440x900      59.89  
   1280x960      60.00  
   1368x768      60.00  
   1360x768      59.80    59.96  
   1152x864      60.00  
   1280x720      60.00  
   1024x768      60.00  
   1024x576      60.00  
   960x540       60.00  
   800x600       60.32    56.25  
   864x486       60.00  
   640x480       59.94  
   720x405       60.00  
   640x360       60.00  
DP1 connected 1920x1200+0+48 (normal left inverted right x axis y axis) 518mm x 324mm
   1920x1200     59.95 +
   1920x1080     60.00  
   1600x1200     60.00  
   1680x1050     59.95  
   1280x1024     60.02  
   1280x960      60.00  
   1024x768      60.00  
   800x600       60.32  
   640x480       60.00  
   720x400       70.08  
   1920x1200_58.00  57.93* 
DP2 connected primary 1920x1200+1920+0 (normal left inverted right x axis y axis) 518mm x 324mm
   1920x1200     59.95 +
   1920x1080     60.00  
   1600x1200     60.00  
   1680x1050     59.95  
   1280x1024     60.02  
   1280x960      60.00  
   1024x768      60.00  
   800x600       60.32  
   640x480       60.00  
   720x400       70.08  
   1920x1200_58.00  57.93* 
HDMI1 disconnected (normal left inverted right x axis y axis)
HDMI2 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)

I'm checking if the issue repeats or not now. If it does not this means that I've got the solution and I'll mark it as answer.

I still do not know how to permanently store these settings, I guess I should add a new file to the /usr/share/X11/xorg.conf.d folder following recommendations in this document. I'm going to study this when I see that the issue is fixed.

Best Answer

If your screen is switching off it might be struggling to keep sync with the output signal.

There are two main reasons for this , the first is refresh rates being too high for the screen to keep up with and the second is the cables are not good enough. There is an outside chance your graphics card can't cope with multiple screens but most are powerful enough.

Which connection method are you using and what resolution are the screens set to ?

Xrandr will allow you set and query the refresh rates. Sometimes knocking a few hz off the frequency can work around bad cables.

If you have other cables you can borrow try them.

you xorg logs (in /var/log/ but check the dates of the files) should show the resync attempts and shed some light as well

Related Question