External Monitor not Detected: Dell Laptop/Dell Monitor

[joellynn]

My software and hardware information are as follows. I have Fedora 12 and KDE 4.4.5 installed on a Dell Vostro 1500 laptop. I believe it's a 64 bit processor; it's an Intel Core 2 Duo CPU. The external monitor is a Dell as well.

My problem is that my system does not seem to be detecting an external monitor that I have connected. Everything else is working just fine; however, I would like to have the option of attaching an external monitor. When I plug the external monitor into the laptop, the external monitor remains black and appears to be in power save mode. The results of xrandr -q (with or without the external monitor attached: it doesn't appear to change) are as follows.

[joel@jelynn etc]$ xrandr -q
Screen 0: minimum 320 x 175, current 1280 x 800, maximum 1280 x 800
default connected 1280x800+0+0 0mm x 0mm
   1280x800       50.0* 
   1024x768       51.0     52.0  
   832x624        53.0  
   800x600        54.0     55.0     56.0     57.0     58.0  
   720x400        59.0  
   700x525        60.0  
   640x512        61.0     62.0  
   640x480        63.0     64.0     65.0     66.0     67.0  
   640x400        68.0  
   640x350        69.0  
   576x432        70.0  
   512x384        71.0     72.0     73.0     74.0     75.0  
   416x312        76.0  
   400x300        77.0     78.0     79.0     80.0     81.0  
   360x200        82.0  
   320x240        83.0     84.0     85.0     86.0  
   320x200        87.0  
   320x175        88.0

How can I get my laptop to recognize that the external monitor is even connected? Let me know if I can be more specific or provide additional details.

Thanks,

Joel

[ADW]

From that output it appears that xrandr does not even acknowledge that other display outputs (VGA, HDMI, etc.) are available, so getting it to do that should be your first step.

For example, when I run "xrandr -q" on my laptop (Dell Inspiron 1525), I get:

Screen 0: minimum 320 x 200, current 1440 x 900, maximum 8192 x 8192
LVDS1 connected 1440x900+0+0 (normal left inverted right x axis y axis) 303mm x 190mm
   1440x900       60.0*+
   1024x768       60.0  
   800x600        60.3     56.2  
   640x480        59.9  
VGA1 disconnected (normal left inverted right x axis y axis)
HDMI1 disconnected (normal left inverted right x axis y axis)
TV1 disconnected (normal left inverted right x axis y axis)

I'm guessing maybe you need a different graphics driver?

[joellynn]

Thanks for the reply ADW. That makes sense as a first step. I'm still something of a novice, so I can't immediately say I know how to get xrandr to recognize that other display options are available. Would it have something to do with editing /etc/x11/xorg.conf? The graphics driver is nVidia. The graphics card is a nVidia Corporation GeForce 8400M GS, or at least that's what I'm gleaning from lspci -v.

01:00.0 VGA compatible controller: nVidia Corporation GeForce 8400M GS (rev a1) (prog-if 00 [VGA controller])
        Subsystem: Dell Device 0228
        Flags: bus master, fast devsel, latency 0, IRQ 16
        Memory at fd000000 (32-bit, non-prefetchable) [size=16M]
        Memory at f4000000 (64-bit, prefetchable) [size=64M]
        Memory at fa000000 (64-bit, non-prefetchable) [size=32M]
        I/O ports at df00 [size=128]
        [virtual] Expansion ROM at fea00000 [disabled] [size=128K]
        Capabilities: [60] Power Management version 2
        Capabilities: [68] MSI: Enable- Count=1/1 Maskable- 64bit+
        Capabilities: [78] Express Endpoint, MSI 00
        Capabilities: [100] Virtual Channel
        Capabilities: [128] Power Budgeting <?>
        Capabilities: [600] Vendor Specific Information: ID=0001 Rev=1 Len=024 <?>
        Kernel driver in use: nvidia
        Kernel modules: nvidia, nouveau, nvidiafb

You think maybe I need a different driver?

[oldcpu]

I do not believe nVidia provide as good 'xrandr' support as is provided by Intel (for Intel graphic hardware) nor AMD (for AMD Radeon HD hardware).

Instead of 'xrandr' you could try the application 'disper'.

or if you have the proprietary nVidia graphic driver installed, I think it comes with an application called 'nvidia-settings' and you could try that.

[joellynn]

Thanks for the reply oldcpu. I did download the disper application. After reading the information in man disper, I tried a few things. I typed disper -l and at least both monitors were listed, so that was an improvement! I then tried disper -c for clone, and disper -e for extend. In both cases, something happened, but it wasn't the desired effect. The mouse was visible in both cases and behaved properly according to if I had typed "c" or "e", but the rest of the display was just black with no apparent way to get it back. I had to restart the X server. So, this might be a disappointed post, but...

nvidia-settings works perfectly for me! I am able to choose the external monitor, configure it, and mess around with different choices for positioning, etc, all within their GUI. I even wondered what would happen when I'm at home and don't have my second monitor attached. Whatever edits it made to the /etc/x11/xorg.conf file, when I start X, it applies the appropriate settings if the external monitor is detected and if it's not. So, hooray! Problem solved.

My thanks to both ADW and oldcpu for advice and suggestions.

Joel

[cryogenic666]

Thanks for the reply oldcpu. I did download the disper application. After reading the information in man disper, I tried a few things. I typed disper -l and at least both monitors were listed, so that was an improvement! I then tried disper -c for clone, and disper -e for extend. In both cases, something happened, but it wasn't the desired effect. The mouse was visible in both cases and behaved properly according to if I had typed "c" or "e", but the rest of the display was just black with no apparent way to get it back. I had to restart the X server. So, this might be a disappointed post, but...

nvidia-settings works perfectly for me! I am able to choose the external monitor, configure it, and mess around with different choices for positioning, etc, all within their GUI. I even wondered what would happen when I'm at home and don't have my second monitor attached. Whatever edits it made to the /etc/x11/xorg.conf file, when I start X, it applies the appropriate settings if the external monitor is detected and if it's not. So, hooray! Problem solved.

My thanks to both ADW and oldcpu for advice and suggestions.

Joel

I'm in the same situation myself. Basically, I just "Apply" the settings, but I don't write them to the xorg.conf file. Right before I go home for the day, I disable the external monitor, which moves all my windows over to my main laptop screen. I close the lid, it goes into sleep. Open it up when I get home and all's well. Then when I come back to work the next day, I just "detect displays", tell it my external is to the left, apply, and good to go. Make sense? Also, by not writing to the xorg.conf, I don't have to worry about accidentally rebooting at home and having a phantom second monitor.