display – TechUtils.in

April 9, 2019

#StackBounty: #laptop #display #multiple-monitors #resolution #hp-spectre Dell dual monitor is unstable with my HP laptop

Bounty: 50

At work, I have a Dell monitor as a dual screen in addition to my HP Spectre laptop screen.

I have a Dell hub that has the monitor, ethernet, mouse and keyboard as inputs, and then this connects to my laptop via USB.

For the most part it works fine, but there is some strange behaviour regarding the monitor. I will try to describe some of the weird things and see if anyone has any idea of a fix.

Firstly, when I take my laptop home and use it alone, I always have to adjust the screen resolution so it looks okay. No problem.

When I use it again the next day at work:

Sometimes the laptop screen comes on and the monitor remains black.
When I go to display settings, sometimes the Dell monitor appears as a display and sometimes it does not. Sometimes it will appear and then disappear and then reappear, every 10 seconds or so.

Sometimes the Dell monitor will be black for a few minutes and then it will just turn on, and everything will look fine.

Sometimes when the system does recognise the Dell monitor, it will have swapped its position with respect to my laptop screen (i.e. the system thinks I have to move my mouse to the right to appear on the Dell monitor, which is actually to the right).

Quite often, I just restart a bunch of times, and on the (say) third time, it will be okay.

I don’t think there are any loose connections because:

Once the monitor is on and appearing fine, it stays like that all day – even if I move it around.
As I said, sometimes, restarting fixes it, even when I don’t touch any cables.

It just seems that my system can’t quite figure out when resolution / how many monitors and it seems to sometimes jump around between two states trying to figure it out. It usually takes me between 10 and 30 minutes to get it stable each morning, and I don’t even really know what is working. I just restart and change resolution and mess around with anything until it decides it is happy.

I don’t know where to start looking for a fix so if anyone can point me in the right direction that would be great thank you.

UPDATE:

Now the Dell monitor never comes on at all – it doesn’t seem to be recognised. Like I said, I’m pretty sure it’s a software issue rather than a connection problem.

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March 24, 2019

#StackBounty: #xorg #multiple-monitors #display #xrandr #xset How to standby a monitor using xset in multi monitor setup?

Bounty: 100

While having two or more monitor working together, Is there any way to put a single one of them on standby/suspend by issuing a command like: xset dpms force suspend? or having a time set for that purpose like: xset dpms 100 0 0 which works on these monitors separately?

I’ve got two monitor working along each other, eDP1 (My Laptop) and VGA1 (An External monitor).

I want each of them to go into suspend/standby mode separately if I’m not directly interacting with them, suppose I’m watching a movie on VGA1, and for an hour and half eDP1 is on doing nothing.

I’m not interested in using xrandor --off --output eDP1 because it’s not fast enough to work with.

I want my monitor to be ready to work, with a simple mouse movement so I’m able to switch between them fast.

Running: Ubuntu 18.04
Window Manager: OpenBox

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March 12, 2019

#StackBounty: #login #multiple-monitors #display #lightdm #display-resolution How to fix login screen (lightdm) orientation and prompt …

Bounty: 50

I have Ubuntu MATE 16.04.6 LTS installed on a system with two monitors.
They act normally when I login to default MATE 1.12.1 session.

But the LightDM login screen looks weird on both screens:

1600×900 normal landscape rotation
1280×1024 left portrait rotation

Details about lightdm:

$ dpkg -l | grep -i lightdm
ii  liblightdm-gobject-1-0:amd64   1.18.3-0ubuntu1.1  amd64  LightDM GObject client library
ii  lightdm                        1.18.3-0ubuntu1.1  amd64  Display Manager
ii  lightdm-gtk-greeter            2.0.1-2ubuntu4     amd64  simple display manager (GTK+ greeter)
ii  lightdm-gtk-greeter-settings   1.2.1-0ubuntu1     all    settings editor for the LightDM GTK+ Greeter
ii  ubuntu-mate-lightdm-theme      16.04.7            all    LightDM theme and default configuration for Ubuntu MATE

$ cat .dmrc 
[Desktop]
Session=mate

I see this on every boot-up and currently I enter my password blindly.

How and where should I fix this problem?

Update: passing nomodeset in GRUB fixes LightDM login, but disables screen rotation of right monitor.

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February 25, 2019

#StackBounty: #display #multiple-monitors Why is my vertical monitor's viewport much smaller than it should be?

Bounty: 50

I have two 1920 x 1080 monitors, one horizontal and one vertical. When visiting this viewport measuring site on on my horizontal one it says 1920 × 947 which is normal. On my vertical one though it says 864 x 1403.

The viewport width is over 200 pixels smaller than it should be! I see no visual clue that could explain such a weird phenomenon: Chrome window correctly fills the screen, the web pages are complete, etc.

Below is a screenshot taken from another site that measures viewport width that shows both the viewport width (847px) calculated by that particular website, and the actual width of the screen as indicated by my screenshot app (1058px).

This looks like black magic. If anybody has the slightest clue please come forward!

This looks like black magic. If anybody has the slightest clue please come forward!

Get this bounty!!!