Undocking M2800 from Advanced E-port II - Black Screen

Hello,

I am new here and hope to get some help.

I have some DELL M2800 (Win7/x64) with AMD FirePro W4170M and Intel HD Graphics 4600.

Docking a M2800  to the EURO Advanced E-port II, I setup 2 monitors (both connected by DVI) to show different content (not cloned). Every thing works fine! The laptop display is off.

But ... if I undock the laptop and open the lid the screen stays black!

If found out that in SOME cases it helps to press Strg+Alt+F8 to get the display to work. And when I wait more that some seconds to press those keys there is no chance to get a picture on the screen. Even if I open the lid while the laptop is still docked the screen on the laptop stays black.

Is there any help available - I tried this on several M2800 with different monitors and different dock stations - all 8 laptops show the same symtoms. I also checked with different driver versions :-(

By the way this problem also accours with only one external monitor connected to the E-Port II!

Thanks for your help.