Second display problem
What often works
With VGA-0
set to 1280x1024
and eDP
connected. run the command (from a terminal):
xrandr --output VGA-0 --pos 0x0 --output eDP --pos 1280x0
which does what should happen automatically after you connected the second screen. The command top- aligns both screens, with eDP
at 1280 from the top-left of VGA-0
.
If this works, as a workaround, add the command to a shortcut key which you can press after connecting the second screen. Choose: System Settings > "Keyboard" > "Shortcuts" > "Custom Shortcuts". Click the "+" and add the command:
xrandr --output VGA-0 --pos 0x0 --output eDP --pos 1280x0
What is the issue?
Graphics drivers seem to be the bottle-neck in many minor incompatibilities. Also in many cases, we can solve it with a small workaround like above.
The exact reason for your issue might be a timing issue, the screen and the driver do not " recognize each other" in time, so the procedure breaks.
Important part is that we can subsequently persuade the system to do the setup with an xrandr
command :).
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Uroboros
Updated on September 18, 2022Comments
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Uroboros over 1 year
Preface: I have a laptop with Ubuntu 16.04 / Windows 10 in dualboot and 2 external displays, one with VGA input, and another with HDMI.
Various times I'm using HDMI display as the second on Windows or Ubuntu, and everything is fine.
When I connect VGA display using Windows, all is well too. But the problem is connecting VGA display with Ubuntu,so, I can use just internal laptop screen or external VGA screen, or even mirror video on both screens, but when I try to use extend mode, all that I see is a black screen on one or another display :(
P.S. My graphics card is AMD Radeon HD 7600m, I'm using open source Radeon driver. Another weird thing: internal display resolution is 1366x768 and external VGA is 1280x1024. When I set 1024x768 instead of usual 1280x1024, it works properly. But using any other resolution leads to black screen.
xrandr
output:Screen 0: minimum 320 x 200, current 2390 x 768, maximum 16384 x 16384 eDP connected primary 1366x768+1024+0 (normal left inverted right x axis y axis) 344mm x 194mm 1366x768 59.93*+ 1280x720 59.86 1152x768 59.78 1024x768 59.92 800x600 59.86 848x480 59.66 720x480 59.71 640x480 59.38 VGA-0 connected 1024x768+0+0 (normal left inverted right x axis y axis) 338mm x 270mm 1280x1024 60.02 + 75.02 1280x960 60.00 1152x864 75.00 1024x768 75.08* 70.07 60.00 832x624 74.55 800x600 72.19 75.00 60.32 56.25 640x480 75.00 72.81 66.67 60.00 720x400 70.08 HDMI-0 disconnected (normal left inverted right x axis y axis)
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Andrea Lazzarotto over 7 yearsWhat graphics card do you have?
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Uroboros over 7 years@AndreaLazzarotto AMD Radeon HD 7600m. Using open source Radeon driver, since proprietary fgrlx is deprecated at 16.04
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Uroboros over 7 years@AndreaLazzarotto Another weird thing: internal display resolution is 1366x768 and external VGA is 1280x1024. When I set 1024x768 instead of usual 1280x1024, it works properly. But using any other resolution leads to black screen. Maybe it'll help to identify the problem...
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Andrea Lazzarotto over 7 yearsThat is relevant information, please include it in the question. Also include the output of
xrandr
. Finally, can you also try the proprietary driver (even if deprecated) for a moment and report if it makes any difference? -
Uroboros over 7 years@AndreaLazzarotto I've added it to the question, including
xrandr
output. As for proprietary driver, I've found info that even if I want, I couldn't install it, since the driver does not support Xorg 1.18 that ships in Xenial. -
Andrea Lazzarotto over 7 years@JacobVlijm shouldn't it be
1280
since the desired resolution is that one? -
Jacob Vlijm over 7 years@AndreaLazzarotto aarrrgh, you are right of course, I blindly took the resolution of xrandr... will re- comment :) Thanks!
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Jacob Vlijm over 7 yearsWhat happens if you run from a terminal :
xrandr output VGA-0 --pos 0x0 --output eDP --pos 1280x0
? (with VGA-0 set to 1280x1024, and the eDP connected) -
Uroboros over 7 years@JacobVlijm It's amazing! I've successfully changed resolution to native after that. But what's the magic? Does it change screens positions relative to each other?
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Jacob Vlijm over 7 yearsHi @Uroboros, posted my answer. please mention if you manage.
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Uroboros over 7 yearsComprehensive answer, just need small syntax fix:
--output...
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Jacob Vlijm over 7 years@Uroboros aarrgh, fixed. Did it by heart. Thanks!