External monitor (VGA output) on my Dell 700m with Ubuntu

I can’t recall if I already posted this, but I did manage to get the VGA output working in order to use a external monitor or projector for my Dell 700m on Ubuntu. For this laptop the Fn-F8 key doesn’t work for whatever reason. Probably some BIOS or motherboard firmware problem that requires a driver in windows. Anyways, trying to use i810switch or i855crt both produce horrible results. Therefore, the only way to get this to work is to enable a dual head configuration.

In order to do this, just add these two Option lines to your xorg.conf file:

Section "Monitor"
        Identifier      "Generic Monitor"
        Option          "DPMS"
        HorizSync       28-64
        VertRefresh     43-60
        Option          "MonitorLayout" "CRT,LFP"
        Option          "Clone" "true"

Found this great page after much searching and most of the configurations work well.

25 thoughts on “External monitor (VGA output) on my Dell 700m with Ubuntu

  1. Once the display is cloned to the VGA output you don’t have to do anything. You should be able to just plug in the monitor and it should work. If it isn’t working than something in you x configuration file is still incorrect. The clone option should simply duplicate the display to another output (or video card).

    What the options here do is that they state that the monitor layout (i.e. the outputs on the video card) are CRT and LCD and that the display should be the same on both.


  2. Thanks–now I have two questions left:

    1) Is that then a mistake in your first option above? Should it read: “MonitorLayout” “CRT,LCD” ?
    2) Since I do not have an entry in my xorg,conf file for “Generic Monitor,” I am unsure where to add the options. To the entry for the Dell monitor?



  3. Well, d’uh! Googled LFP, see that it means “Local Flat Panel” and indicates the notebook display. Never saw that before…


  4. Got it! Put the two options at the end of the first entry of the Monitor section, which was my Dell laptop, and as soon as I exited the session and re-entered X, it worked fine! Thanks for your help.

    Now: have you figured out how to toggle off the screen somehow?


  5. That’s the hard part. You are cloning the screen so you can’t turn it off. The whole thing boils down to the crappy Intel video card the laptop has. Really annoying. Anyways, eventually someone might get fed up with it and fix the Linux device driver that controls the VGA output, but until then we are kinda screwed.


  6. Was curious if you had tried anything related to the new Intel open source drivers to get this to work better? Would love to have spanning monitors (ie Xinerama esk) with my 700m and an external monitor in addition to mirroring. Ever tried this. I am going to try your conf edits to see if I can get this to work as well. Thanks for the post on this. Have you noticed a drain on battery with this?


  7. Brian,
    Thanks, the site you reference worked great. I am running 1280×800 on my laptop screen and 1600×1200 on the external screen connected to it in xinerama mode. Working well! Now I just need to be able to select server layouts from GDM so when I log in I pick laptop mode or xinerama mode. If I resolve that I will return and post the info.

    take care


  8. Hi,

    I also have a Dell 700m laptop.
    I bought a LCD monitor this week.
    I run Linux Ubuntu Dapper.

    I’ve been fighting for three looong nights with my laptop and it still doesn’t work…
    What works:
    – I can clone my laptop’s screen on the external monitor (resolution for both monitors: 1024×768)
    – I can use xinerama, and both screens are working together.

    What does NOT work (yet)
    – I cannot get the 1280×1024 resolution on my external LCD monitor… it’s such a pain :-/ The best resolution I get is 1024×768.

    What I would like is either:
    – Laptop screen (1280×800 – this is my current resolution) + external LCD screen (1280×1024) with the clone property
    – Only external screen (1280×1024) – nothing displayed on the laptop’s screen (I don’t know if this is possible… I mean getting the ouput only on the external monitor)

    Do you have any idea on this ?



  9. Hi,

    I finally managed to get my external monitor working ! 🙂 I’m happy !
    I have a Dell 700m and an external L1919S.
    Here is what I do:
    when GRUB shows up, I press Fn+F8, then the output is redirected to my external monitor.
    Then, I just have to change the resolution of the screen by adding in the modes: “1280×1024”
    Modes “1280×1024” “1280×800” “1024×768”
    And then, it just works !
    I have the output on my external LCD monitor (with a 1280×1024 resolution) and nothing on the laptop… exactly what I wanted 🙂
    And when I restart my laptop without pressing Fn+F8 when GRUB shows up, the display is as usual on my laptop at 1280×800… it’s great !


  10. tatare’s solution worked for me.

    I have an insprion B130 I didnt have to modifiy the xorg.conf file at all. I would press Fn+f8 at boot and display would show on external monitor/tv but when gdm would launch it would kill the display on the external monitor/tv. What my problem was i had a patch to correct my resolution on boot which was 855resolution. I disabled that and then rebooted and it didnt execute that script and it works great now.


  11. Hi,
    tatare’s solution worked for me as well! Thanks!

    By editing xorg.conf I was trying resolution 1280×1024 on an external monitor to my Thinkpad X60s (which has 1024×768)… without success… Fn+F7 at GRUB works perfect!


  12. These instructions are for a laptop with an nVidia card and not for the Intel card that many Dell laptops use. Just wanted to make sure folks didn’t go down a rabbit hole with that link. If you have an Intel card (you should be able to use lspci to find out), this won’t work, but the latest Intel driver might. That driver did not work on my Dell 700m, just in case anyone is wondering.


  13. Ok, I added this into my xorg.conf file, I get the VGA signal output to the 2nd monitor, while rebooting, as soon as I get to the login screen the monitor isn’t getting any input from VGA output and goes into power saving mode.

    Any help would be appreciated,


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