Score:1

Ubuntu

The monitors don't turn off completely, they stay black with the backlight on

Luis

8/26/24, 1:34 AM

I have ubuntu 22.04 and an nvidia 1050 Ti graphics card to which I have two (3840x2160) monitors connected, one on the HDMI-0 output and the other on the DP-0.

When the energy saving options should be turned off, the two monitors remain black but with backlighting. If I choose in the "monitor configuration" "Single screen" they turn off completely (I have tried with both monitors).

In "Mirror" and "Join screens" they are not turned off. I want to work on "Join screens" I have tried with the Xrandr command in a keyboard shortcut:
xrandr --output HDMI-0 --off
sleep 10
xrandr --output DP-0 --off
but, they don't turn off completely either. Any idea how to get it? Thank you.

I copy here the output of xset -q that does not fit in comments:

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:  500    repeat rate:  33
  auto repeating keys:  00ffffffdffffbbf
                        fadfffefffedffff
                        9fffffffffffffff
                        fff7ffffffffffff
  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:  0
Colors:
  default colormap:  0x20    BlackPixel:  0x0    WhitePixel:  0xffffff
Font Path:
  /usr/share/fonts/X11/misc,/usr/share/fonts/X11/Type1,built-ins
DPMS (Energy Star):
  Standby: 300    Suspend: 400    Off: 600
  DPMS is Enabled
  Monitor is On

I will provide more information about my equipment in case it is relevant to the problem: My motherboard is X670E ROG Crosshair Hero by ASUS (release year 2022) and AMD Ryzen 9 7900 processor (release year 2023) When ubuntu 22.04 boots, it reports some errors:

ACPI BIOS Error (bug): Could not resolve symbol[\_SB.PCIO.GPP7.UP00.DP40.U
P00.DP68], AE_NOT_FOUND (20221020/dswload2-162)
ACPI Error: AE_NOT_FOUND, During name lookup/catalog (20221020/psobjet-220)
i2c i2c-0: Failed to register i2c client ITE8853:00 at 0x4e (-16)
hub 12-0:1.0: config failed, hub doesn't have any port! (err -19)

The processor has integrated graphics. I have tried with the integrated graphics disabled and enabled in the UEFI. I have also tried to connect a monitor to the graphics output of the motherboard and another to the graphics card. With all these tests I can't get that if there are two monitors connected they turn off to save energy.
If there is only one monitor connected it works as expected.

1 + 0

nvidia

multiple-monitors

Score:0

Ubuntu

user10489

8/26/24, 7:51 AM

If you want them to turn off completely, you need to enable dpms.

xset +dpms

Then you can either force the screen off immediately, or enable a time out, use one of

xset dpms force off
xset dpms 300 400 600

If you use the first command, you may want to put a short sleep before it so mouse movement doesn't immediately wake it back up.

You state:

When the energy saving options should be turned off, the two monitors remain black but with backlighting.

This is what it is suppose to do when dpms energy saving options are turned off. (xset -dpms) Perhaps one of the other things you mention is turning it back on. You can check with xset -q

Note that many things (games, full screen apps, gnome itself) mess with dpms and screensaver timings, so these settings are not permanent and are frequently stepped on after you change them.

+ 6

Luis

8/26/24, 10:08 AM

Thanks for the reply. I have executed the proposed code, the two monitors turn off completely for two seconds (without backlight), after two seconds they turn on again. I have unplugged the mouse to prevent it from interfering. Can you think of anything else I can try?

user10489

8/26/24, 12:58 PM

Did you try it with a sleep before it? Pressing enter to run the command might also wake it up.

Luis

8/27/24, 12:22 AM

Yes, I have put the code in the terminal and I have also tried it with a file that I call from a keyboard shortcut. With both methods I get the same result, the monitors turn off and two seconds later they turn on. The monitors turn off after 2 minutes without activity, which is the time that I have programmed in the "Turn off the screen" setting of the "Power saving options" of the Ubuntu 22.04 configuration menu. They actually turn off for two seconds and then go black with the backlight, that is, they continue to draw power and give off heat.

user10489

8/27/24, 12:35 AM

output from `xset -q` would be interesting.

Luis

8/28/24, 9:47 PM

I have put the output of the command in the question and I have added more information about the hardware components of my computer.

user10489

8/29/24, 11:32 AM

When I get a chance, I'll research the hardware and see if there are known issues (bugs).

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: The monitors don't turn off completely, they stay black with the backlight on

Post an answer

Most people don’t grasp that asking a lot of questions unlocks learning and improves interpersonal bonding. In Alison’s studies, for example, though people could accurately recall how many questions had been asked in their conversations, they didn’t intuit the link between questions and liking. Across four studies, in which participants were engaged in conversations themselves or read transcripts of others’ conversations, people tended not to realize that question asking would influence—or had influenced—the level of amity between the conversationalists.