Hey everybody! Time for another fix.
This one gave me a real headache: after I logged in in my HP Elitebook 850 using Linux Mint 17.1 Cinnamon Edition, my external VGA monitor went black. Everything was fine while booting (the splash screen appeared on both screens) and in the login screen, but as soon as I logged in, there was nothing. I immediately went to see if my xrandr output and monitors.xml (.config/monitors.xml) file. The monitor didn’t show up in the xrandr, but there were some signs of problems in the monitors.xml, as shown bellow. xrandr:
<code>Screen 0: minimum 320 x 200, current 1366 x 768, maximum 32767 x 32767 eDP1 connected primary 1366x768+0+0 (normal left inverted right x axis y axis) 344mm x 194mm 1366x768 60.0*+ 40.0 1360x768 59.8 60.0 1024x768 60.0 800x600 60.3 56.2 640x480 59.9 DP1 disconnected (normal left inverted right x axis y axis) HDMI1 disconnected (normal left inverted right x axis y axis) DP2 disconnected (normal left inverted right x axis y axis) HDMI2 disconnected (normal left inverted right x axis y axis) VIRTUAL1 disconnected (normal left inverted right x axis y axis)</code>
Extract of monitors.xml:
<configuration> <clone>no</clone> <output name="eDP1"> <vendor>CMN</vendor> <product>0x15be</product> <serial>0x00000000</serial> <width>1366</width> <height>768</height> <rate>60</rate> <x>0</x> <y>0</y> <rotation>normal</rotation> <reflect_x>no</reflect_x> <reflect_y>no</reflect_y> <primary>yes</primary> </output> <output name="DP1"> </output> <output name="HDMI1"> </output> <output name="DP2"> <vendor>???</vendor> <product>0x0000</product> <serial>0x00000000</serial> </output> <output name="HDMI2"> </output> <output name="VIRTUAL1"> </output> </configuration>
To solve this problem, my solution was:
- Reboot the computer, and wait for grub (you might have to hold shift or other keys to force the grub to appear)
- At the GRUB boot menu select the correct line but don’t press Enter. Press the “E” key to edit.
- Using the Down arrow key, go down to the line that starts with: linux /boot/vmlinuz………….ro quiet splash $vt_handoff
- In the end of that line, write: video=DP2:d
- Press F10
- Wait for the login screen to appear. When it does, press Ctrl+Alt+F1.
- Login in the terminal that appears, and execute this command to cleanup and backup the monitors file: mv .config/monitors.xml .config/monitors.xml.bak
- Logout (exit) and press Ctrl+Alt+F7 (or F8) to come back to the Mint login screen
- Login as usual
This reverted my monitor back to normal.
Now, I only need to make these changes permanent! To do that, I just need to edit /etc/default/grub (with, for instance, the command sudo nano /etc/default/grub and make the changes. After that, I run sudo update-grub to update the grub with the just updated changes.
I hope this helps if anyone else has the same problem! If you need more information or help, please comment bellow. I’ll give my best to provide feedback!
I tried to follow the steps but there’s no file in .config/monitors.xml. I tried searching for it in various dir but couldn’t find it. Also does the change in the grub remain or does it clear out after it boots? Reason I ask is when went back to check, my changes didn’t appear. I’m a novice btw
The .config/monitors.xml file is created by the Gnome monitor settings program. If you do not have the file, don’t worry, just keep going with the instructions. I just rename it to make sure Gnome (or, in this case, Cinnamon) creates new settings, and doesn’t load the old, corrupt ones.
Either way, did it work for you? Could you get the monitor working after the login? The grub change is temporary. If the change works for you, you can set it to default by doing the step I just added to the post above! I forgot about that!
If you have any more troubles, please say so!
It didn’t work but I starting looking around the logon screen and clicking on available items. The one item that actually fixed it for me was this little icon next to the country flag (mine being USA) it had an icon that looks like an upside down V. When I click on it, it gave me options to select. I saw Mint and selected that. Walla! my desktop is back! Not sure if that’s the right thing to do but everything appears to be working. by the way, the icon changes to an M.
I’m not sure if I accidentally changed this or if it was done by the latest updates but I never really looked at that icon before. So I don’t know if it was always this way (upside down V).
Thanks for your tip anyways! Hope it helps someone else.
You’re talking about the Desktop Environment list. You probably had the choice to load the last used DE, which usually is listed as an λ.
Glad you fixed your problem!
Yes, that’s how it looked like!
Thanks so much for posting this!
I have an HP 840g that I recently installed Mint 17.3 ‘Rosa’ on.
I had this same problem occurring over the VGA port (also DP2 on my laptop) after I tried to connect to a projector.
Deleting the offending `~/.config/monitors.xml` allowed the VGA to be used with my DisplayPort monitor again.