Hi Andre I have a T440s and had a similar problem. However, at least in my case, the solution was quite simple: the built-in screen is not blank, only its brightness is reduced to 0 (for some stupid reason) when an external monitor (or in my case a beamer) is connected. In order to bring your built-in screen 'back', simply increase its brightness with the F6 function key. At least this worked for me.
regards Eugen PS: let me know if this solution worked for you too. On Wed, 2015-04-08 at 10:06 +0200, André Pinto wrote: > Also, I don't know if that is relevant or not, but I'm using the Mini > DisplayPort connector to connect to the external monitor. > > > On Wed, Apr 8, 2015 at 10:03 AM, André Pinto > <andredasilvapi...@gmail.com> wrote: > Hi, > > > I'm having problems with having both the built-in display of > my Thinkpad T440s and an external monitor working. If I boot > the system without the external monitor connected, the > built-in display works, but as soon as I connect the external > monitor the external monitor starts working and the built-in > display goes blank. If I boot with the external monitor > connected, the initial boot screens (bios, grub...) show up on > the built-in display but as soon as I get to the GDM login > screen it goes blank and only the external monitor works. > > > In any of these cases, even if I disconnect the external > monitor after the built-in display stops working, it doesn't > start working again (i.e. it is not "re-enabled"). > > > Both of the displays are properly enabled in the Displays > configuration screen (I've tried with both primary-secondary > and secondary-primary configurations, the problem is the > same). > > > > Do you have any ideas about how can I solve this problem? Is > it a known issue with the T440s? > > This is the debian version that I'm using: > 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt7-1 (2015-03-01) x86_64 > GNU/Linux > > > Thanks in advance, > > André. > > >
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