Arch Linux

obelisk

Member

From: Germany

Registered: 2021-01-10

Posts: 76

[SOLVED] Monitor gets on/off in a loop during Suspend to RAM &shutdown

Hi, I have observed that my monitor screen gets on/off during suspend to RAM.
Same behaviour, when I shutdown my PC and do no disconnect the power supply from 230V.

The monitor gets pn for approx. 2 seconds. Then it get off again for some seconds, but mostly below 1 minute it gets on again. An that in a loop.

The PC the whole time in suspend or shutdown.

I'm having this for longer time, and I didn't figure out it it is a problem from operating system, the graphics card or from the monitor.
Maybe somebody has an idea...

Graphic card: Nvidia GeForce RTX 4070. My old Nvidia 1050Ti had the same issue. I was hoping that the new card will solve this, but it's still the same.

Monitor: Samsung U32J59x, connected via Displayport
The Samsung monitor has a option to deactivate the automatic source detection; the automatic source detection is set off.

Some informations:

$ uname -r
6.7.7-arch1-1

$ nvidia-smi -q -i 0 | grep -i "driver version"
Driver Version                            : 550.54.14

$ cat /etc/X11/xorg.conf.d/20-nvidia.conf
Section "ServerLayout"
    Identifier 	"Layout0"
    Option "OffTime"		"20"
EndSection

Section "Screen"
    Identifier	"Screen0"
    Device	"Device0"
    Monitor	"Monitor0"
EndSection

Section "Monitor"
    Identifier	"Monitor0"
    VendorName	"Samsung"
    ModelName	"U32J59x"
    DisplaySize 700 390
EndSection

Section "Device"
    Identifier	"Device0"
    Driver	"nvidia"
    Option      "ConnectToAcpid" "0"
    Option	"DPI" "139 x 140"
    Option	"MetaModes" "DP-0: 3840x2160+0+0 {ViewPortIn=3840x2160, ViewPortOut=3840x2160+0+0}"
EndSection

$ pacman -Qs acpi
(not installed)

Tell me, if more information's are needed.
I think it a stupid setting or its the Samsung monitor. Unfortunately, I have no other monitor fo testing.

Last edited by obelisk (2024-03-19 10:44:10)

obelisk

Member

From: Germany

Registered: 2021-01-10

Posts: 76

Re: [SOLVED] Monitor gets on/off in a loop during Suspend to RAM &shutdown

Today I accidentally found the cause and at the same time the solution.

The Problem in short:
When PC is normal turned off/shutdown and not disconnected from 230V AC, then Monitor backlight get of/off in a loop every some seconds.
Same behaviour, when I disconnect all DP and HDMI input cables from monitor, and let just the power supply connected.

The cause:
I have next to the table a small audio amplifier, which is driven by an 19V laptop power supply unit. This PSU is always connected to 230V (the amplifier has a on/off switch itself).
Today I found a side effect: When the amplifer PSU is disconnected from 230V, then the Monitor stays off how it should be.
When I just connect the amplifier PSU to 230V and also let the amplifier on/off switch in off-position, then the Samsung Monitor begins to switch on/off the backlight in a loop. The power cable of the amplifier is close to the display port cable.

So it is no problem from graphic card. It's just some kind malfunction with radiation from the amplifier power supply unit.
Topic is solved for me, root cause is not the PC, graphic card or archlinux