external video undetected

[bodhidharma]

I'm running Lucid on a new Lenovo T420 (I heard mixed reviews of Unity, so I'm just keeping with a version which I like...) and the machine does not detect an external monitor. Does anyone have any idea of why not? In the past, I would just plug in the video cable and go to System->Preferences->Monitors and see it, it was great.

Hmm, actually, I think I often used the function key F7 to switch without any GUI tool being involved. Anyway, it was painless and obvious on my last ThinkPad, now I cannot do it at all. This is embarrassing when you go to give a talk and have the machine but cannot use it....

Any ideas?

[noob89]

I have the same problem. I'm trying to use an external monitor and when I go to System Settings->Display my laptop screen is there listed as "Unknown." I'm running 11.10 with Unity on my Lenovo T410. I'm very new to Linux and I have no idea what to do.