Display port monitor not turning on after turned off Ubuntu 22.04.3

Patrick Lacson

8/17/24, 3:04 PM

I have an odd problem. When my monitor is manually turned off or goes to power-saving mode, Ubuntu won't detect it when I try to turn on the monitor. I see a blank screen where the DisplayPort input screen is trying to pick up a signal but nothing.

This is a good monitor and my mac is able to turn on the screen when it wakes up from power saving mode.

My PC is a Dell Optiplex Tower Plus 7010 built in Aug 9, 2023. It's a brand new computer.

I've tried the following suggested solutions:

Turn off secure boot on BIOS
Disable auto in bios for display, but forced it only to on-board graphics (I don't have external graphics card)

My only work around is to ssh into the machine and do sudo reboot.

Any working solutions would be greatly appreciated!

1 + 0

dell

displayport

22.04

Score:0

Ubuntu

ZuBB

8/17/24, 4:52 PM

my answer does not have steps to 100% solve your issue. but it should help you to narrow it down or find a guilty one.

The 1st thing is to find out if this is a hardware problem or software.

To ensure this is not a hardware problem, you (ideally) need to put MSWin (either live or fully installed) on your new PC. And then do your test.

test does not pass - means a high probability of buggy hardware. There is also some (small) chance that failed test does not mean bad hardware. Bugs in firmware might be the case
test passes - means hardware is ok. You need to move to software tests.

I tend to believe its a software thing

The 2nd thing is to find out which software piece does not do its job.

I see two pieces that might be involved here: the Linux kernel itself and the driver for integrated video card. You need to check both of them to see if they support your hardware (CPU generation, chipset, GPU, etc). There are 3 possible cases here

super luck -- support of it is in already released versions. You need to find and install those versions.
tiny luck -- support of it has been committed but not released. You need to find and install those snapshots.
no support has been added yet. You need to wait and follow their mailing list, GitHub, or whatever they use.

Off-top: did you check if that PC has the official support of any Linux distro before buying it?

+ 2

ZuBB

8/17/24, 4:59 PM

2nd thought: under "driver for integrated video card" I mean userland's driver. but I realized it most probably has a few other responsibilities. so your main target is the kernel (and intel's driver within it)

Patrick Lacson

8/21/24, 10:26 PM

Update: Works on a Dell monitor. On my Samsung 34-inch ultrawide it is picky. My Ubuntu powered Lenovo Thinkcenter works when monitor is turned off via display port. But my Optiplex Tower Plus 7010 does not. Same cable, same monitor, same OS Ubutnu 20.04.3 LTS.

Elon Musk

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

EN: Display port monitor not turning on after turned off Ubuntu 22.04.3

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