Take the 2-minute tour ×
Ask Ubuntu is a question and answer site for Ubuntu users and developers. It's 100% free, no registration required.

I have a Dell laptop with an external monitor attached (a Samsumg SyncMaster 931c).

My laptop display was recognized, and I can adjust its optimum resolution.
My external display is still unknown, thus I'm stuck at a lower resolution (1024x768):

enter image description here

I tried the "Detect Displays" button, but it didn't work, nothing happens.

I recently upgraded from Ubuntu 12.04 to 12.10.
Things were working before.
I don't know if I can actually change this configuration, or if this is a bug.

I searched for an answer here and also in Launchpad's website, but found none.

I even tried to install Nvidia drivers, and just messed things up.
It seems I wasn't even using nvidia before, as I guessed by looking at my additional drivers configuration:

enter image description here

My laptop has an Intel chipset, I guess:

$ dpkg --get-selections | grep -i -e nvidia -e intel
intel-gpu-tools                 install
libdrm-intel1:amd64             install
libdrm-intel1:i386              install
nvidia-common                   install
xserver-xorg-video-intel            install

I don't have an xorg.conf file (I think this is nvidia related, am I right?):

$ cat /etc/X11/xorg.conf
cat: /etc/X11/xorg.conf: No such file or directory

$ ls -l /etc/X11/
total 76
drwxr-xr-x 2 root root  4096 Out 19 23:41 app-defaults
drwxr-xr-x 2 root root  4096 Abr 25  2012 cursors
-rw-r--r-- 1 root root    18 Abr 25  2012 default-display-manager
drwxr-xr-x 4 root root  4096 Abr 25  2012 fonts
-rw-r--r-- 1 root root 17394 Dez  3  2009 rgb.txt
lrwxrwxrwx 1 root root    13 Mai  1 03:33 X -> /usr/bin/Xorg
drwxr-xr-x 3 root root  4096 Out 19 23:41 xinit
drwxr-xr-x 2 root root  4096 Jan 23  2012 xkb
-rw-r--r-- 1 root root     0 Out 24 08:55 xorg.conf.nvidia-xconfig-original
-rwxr-xr-x 1 root root   709 Abr  1  2010 Xreset
drwxr-xr-x 2 root root  4096 Out 19 10:08 Xreset.d
drwxr-xr-x 2 root root  4096 Out 19 10:08 Xresources
-rwxr-xr-x 1 root root  3730 Jan 20  2012 Xsession
drwxr-xr-x 2 root root  4096 Out 20 00:11 Xsession.d
-rw-r--r-- 1 root root   265 Jul  1  2008 Xsession.options
-rw-r--r-- 1 root root    13 Ago 15 06:43 XvMCConfig
-rw-r--r-- 1 root root   601 Abr 25  2012 Xwrapper.config

Here is some information I gathered by looking at other related posts:

$ sudo lshw -C display; lsb_release -a; uname -a
  *-display:0             
       description: VGA compatible controller
       product: Mobile 4 Series Chipset Integrated Graphics Controller
       vendor: Intel Corporation
       physical id: 2
       bus info: pci@0000:00:02.0
       version: 07
       width: 64 bits
       clock: 33MHz
       capabilities: msi pm vga_controller bus_master cap_list rom
       configuration: driver=i915 latency=0
       resources: irq:48 memory:f6800000-f6bfffff memory:d0000000-dfffffff ioport:1800(size=8)
  *-display:1 UNCLAIMED
       description: Display controller
       product: Mobile 4 Series Chipset Integrated Graphics Controller
       vendor: Intel Corporation
       physical id: 2.1
       bus info: pci@0000:00:02.1
       version: 07
       width: 64 bits
       clock: 33MHz
       capabilities: pm bus_master cap_list
       configuration: latency=0
       resources: memory:f6100000-f61fffff
LSB Version:    core-2.0-amd64:core-2.0-noarch:core-3.0-amd64:core-3.0-noarch:core-3.1-amd64:core-3.1-noarch:core-3.2-amd64:core-3.2-noarch:core-4.0-amd64:core-4.0-noarch:cxx-3.0-amd64:cxx-3.0-noarch:cxx-3.1-amd64:cxx-3.1-noarch:cxx-3.2-amd64:cxx-3.2-noarch:cxx-4.0-amd64:cxx-4.0-noarch:desktop-3.1-amd64:desktop-3.1-noarch:desktop-3.2-amd64:desktop-3.2-noarch:desktop-4.0-amd64:desktop-4.0-noarch:graphics-2.0-amd64:graphics-2.0-noarch:graphics-3.0-amd64:graphics-3.0-noarch:graphics-3.1-amd64:graphics-3.1-noarch:graphics-3.2-amd64:graphics-3.2-noarch:graphics-4.0-amd64:graphics-4.0-noarch:printing-3.2-amd64:printing-3.2-noarch:printing-4.0-amd64:printing-4.0-noarch:qt4-3.1-amd64:qt4-3.1-noarch
Distributor ID: Ubuntu
Description:    Ubuntu 12.10
Release:    12.10
Codename:   quantal
Linux Batcave 3.5.0-17-generic #28-Ubuntu SMP Tue Oct 9 19:31:23 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux

$ xrandr -q
Screen 0: minimum 320 x 200, current 2304 x 800, maximum 32767 x 32767
LVDS1 connected 1280x800+0+0 (normal left inverted right x axis y axis) 286mm x 1790mm
   1280x800       59.9*+
   1024x768       60.0  
   800x600        60.3     56.2  
   640x480        59.9  
VGA1 connected 1024x768+1280+32 (normal left inverted right x axis y axis) 0mm x 0mm
   1024x768       60.0* 
   800x600        60.3     56.2  
   848x480        60.0  
   640x480        59.9  
DP1 disconnected (normal left inverted right x axis y axis)
  • If there's anything else I can do, any other information I can post here, to help me configure this external display, please let me know.
  • If this is actually a bug, I apologize (I know bugs are not allowed here), but I really wasn't sure. And I will promptly file a bug report in Launchpad if that's the case.

Thanks a lot in advance. ;)

share|improve this question
    
I did not see it in your post but I assume hitting the "detect display" did nothing? My 2nd monitor was detected when I hit that button ;) –  Rinzwind Oct 25 '12 at 14:57
    
Hi @Rinzwind, you're right, I tried the "Detect Displays", but it didn't work. I've edited the question with this information. Thanks. :) –  WagnerAA Oct 26 '12 at 13:16
    
If you want to be sure about your CPU, you can use this command; cat /proc/cpuinfo –  jeremiah Jul 10 '13 at 8:38

2 Answers 2

up vote 6 down vote accepted

The monitor cable was loose.
When I removed the cable and firmly plugged it in again, everything suddenly worked.
The monitor was recognized, and now I am using my previously desired resolution: The monitor was recognized

I feel kind of silly, because I never thought merely touching a loose cable would be of any help.

share|improve this answer
    
So, it's fine now. Right? –  TomKat Oct 27 '12 at 8:06

1] There are some tools to automate the switching between monitors. you can use this tools, to automate it RandR, disper, displex or this one http://gnomefiles.org/content/show.php/Laptop+external+display+hotplugging?content=138742

2] Else, you may use the command xrandr to check if external monitor is connected. Then, create a script file that automatically uses your favourite resolution when the monitor is connected.

DO NOT connect it to the monitor now. Reboot, choose your favourite resolution and run

$ sudo cp /etc/X11/xorg.conf /etc/X11/xorg.undock

Connect monitor now, and reboot. Choose your new favourite resolution and run

$ sudo cp /etc/X11/xorg.conf /etc/X11/xorg.dock

Make a script file and add it to autorun:

# Check if system is docked or undocked and use correct xorg.conf file.
# <lm_name> is name of laptop monitor
DOCKED="`hwinfo --monitor | grep "<lm_name>" | wc -l`" 
# Next line is for debugging
# echo $DOCKED > /root/docked-state.txt 
if [[ $DOCKED = "0" ]] 
then 
cp /etc/X11/xorg.dock /etc/X11/xorg.conf 
else 
cp /etc/X11/xorg.undock /etc/X11/xorg.conf 
fi 
# End of dock-undock script 

If the script doesn't work, replace DOCKED="hwinfo --monitor | grep "<lm_name>" | wc -l" # Next line is for debugging # echo $DOCKED > /root/docked-state.txt if [[ $DOCKED = "0" ]] then with if xrandr -q |grep -q "VGA-0 connected" ; then and run.

share|improve this answer
    
Hi TomKat. I don't have an xorg.conf file, so I didn't even try the rest of your solution. I've already edited the question with this information. Thanks anyway. ;) –  WagnerAA Oct 26 '12 at 13:18
    
I see this line in your result: -rw-r--r-- 1 root root 0 Out 24 08:55 xorg.conf.nvidia-xconfig-original Change the code accordingly. Will work. :-) –  TomKat Oct 26 '12 at 14:07
    
Hi! I've tried to install your 1) option software. It doesn't have a Quantal package, I had to change the PPA to a Oneiric package. And it didn't work, Ubuntu complains with an automated bug report on every launch. :/ –  WagnerAA Oct 27 '12 at 3:07
    
Try the script; it has worked on a few 12.10 systems I know, and also on another AU user's. –  TomKat Oct 27 '12 at 8:05

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.