Arch Linux

quiedoH

Member

Registered: 2022-01-22

Posts: 3

troubleshooting DisplayPort

Dear all,
been running Arch for quite a while now, mostly without problems.

But today the most strange thing happened: The completely blank (black) screen on about 1yr old LG monitor, connected through a display port. Completely unresponsive, adrenaline rushing in; ssh'ing into my machine just to make sure that the OS was running, and apparently all was fine. Switched to HDMI cable, and, bang, lights came back up on the screen!

How do I even begin to figure out whether there is something amiss on the OS side? It's probably a stupid question, but how do I inspect display/monitor properties when display is not responsive?

The following was produced when the monitor was connected with HDMI cable.

xrandr -q

Screen 0: minimum 320 x 200, current 2560 x 1440, maximum 16384 x 16384
DP-1 disconnected (normal left inverted right x axis y axis)
HDMI-1 disconnected (normal left inverted right x axis y axis)
HDMI-2 connected 2560x1440+0+0 (normal left inverted right x axis y axis) 600mm x 340mm
   2560x1440     59.95*+
   3840x2160     30.00    30.00    25.00    24.00    29.97    23.98  
   1920x1080     60.00    50.00    59.94    30.00    24.00    29.97    23.98  
   1600x900      60.00  
   1280x1024     60.02  
   1280x800      59.91  
   1280x720      60.00    59.94  
   1024x768      60.00  
   800x600       60.32  
   720x576       50.00  
   720x480       60.00    59.94  
   640x480       60.00    59.94  
DP-2 disconnected (normal left inverted right x axis y axis)
HDMI-3 disconnected (normal left inverted right x axis y axis)

This is my first post, please have patience

Head_on_a_Stick

Member

From: The Wirral

Registered: 2014-02-20

Posts: 9,003

Website

Re: troubleshooting DisplayPort

Perhaps load up a (graphical) live ISO to check for hardware failure. A bad cable and/or connector would be the most likely cause, I think.

---

Jin, Jîyan, Azadî

seth

Member

From: Won't reply 2 private help req

Registered: 2012-09-03

Posts: 77,100

Re: troubleshooting DisplayPort

Intel?
https://bbs.archlinux.org/viewtopic.php?id=273480

---

How to upload text · How to boot w/o GUI · Disable Windows Fast-Start! · Fix your xinitrc

quiedoH

Member

Registered: 2022-01-22

Posts: 3

Re: troubleshooting DisplayPort

seth, yes.

lshw -short 

/0/1                         processor      Intel(R) Core(TM) i7-10510U CPU @ 1.80GHz
/0/100/2                     display        CometLake-U GT2 [UHD Graphics]
.. 

$ uname -r
5.15.16-1-lts

Let me know if I can provide further information to hopefully resolve the issue and return to using the DP.
I am looking for another DP cable to check for cable failure as well.
A quick look at dmesg didn't show anything unusual.

Thanks Head_on_a_stick and seth for quick responses.

Last edited by quiedoH (2022-01-25 11:40:24)