DPMS turns screen off, but turns back-light on intermittently, and does not allow it to sleep.


So I’ve been having an issue with turning the screen off via DPMS. Basically, if I do

xset dpms force off

or suspend/standby

Or if I just wait for the specified timeout for the screen to turn off, the monitor will turn off for a few seconds, and then show a box saying “No Video Signal Detected” and another box saying “Going into sleep mode”. The monitor then goes into sleep mode, where the power indicator blinks. But after 20 - 30 sec, the monitor back light turns back on, and displays the same two boxes again, before going back into sleep mode. The monitor then continues looping like this until I move the mouse and wake it, in which case the monitor turns back on.

This is my output for

xset dpms -q
Keyboard Control:
  auto repeat:  on    key click percent:  0    LED mask:  00000002
  XKB indicators:
    00: Caps Lock:   off    01: Num Lock:    on     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:  600    repeat rate:  25
  auto repeating keys:  00ffffffdffffbbf
  bell percent:  50    bell pitch:  400    bell duration:  100
Pointer Control:
  acceleration:  2/1    threshold:  4
Screen Saver:
  prefer blanking:  yes    allow exposures:  yes
  timeout:  0    cycle:  600
  default colormap:  0x22    BlackPixel:  0x0    WhitePixel:  0xffffff
Font Path:
DPMS (Energy Star):
  Standby: 360    Suspend: 540    Off: 720
  DPMS is Enabled
  Monitor is On
Font cache:
  Server does not have the FontCache Extension

And my output for


(partial paste)


Maybe try setting screensaver cycle equal to or less than DPMS standby?

Which WM or DE do you use?

Does it happen with the webcam disconnected?