Dell Latitue E6420 and e-port replicator PRO2X

Nice one, I have exactly the same issue in exactly the same scenario with my Dell Inspirion E5420. Lid closed, external screens hooked up and I also do not see a picture on the external screen.

I tried DisplayPort, DVI Digital connections, different Monitors  and it is the same with every digital connection with ever external screen. The notebook outputs the POST messages and you can even enter the BIOS while the lid is closed. You will also see the "Starting Windows" message, the orbing animation even. That's it. You will hear the Windows startup sound.

The external screen signal is lost during the boot up, then the screen enters power save mode. No picture. Try this to get the picture back: open the lid and close it. This seems to trigger the digital output and you will then see the Windows Logon screen on the external monitor. But the dock combined with a Dell notebook to use the notebook with the lid closed is pretty useless.

Plus the audio signal is not output over the DisplayPort cable. Therefore I have now removed the E-Port Plus dock and do what I did for the last year with my old HP notebook: Open the lid, pressing the power button, close the lid and enjoy the picture using the direct HDMI out from the notebook. The audio signal is also sent over HDMI.

In a nutshell: do not invest in the E-Port Plus, it is not working as expected and a waste of money.

Besides, what the Dell E-Port plus can't do, every Lenovo dock notebook combination works perfectly fine with the same setup. Shame on Dell for not even providing a solution for this (and I don't even bother to call support, I am experienced enough to see that this is not a driver or BIOS issue, both are the latest available, even A05 is installed). It is simply not working and no one is able to fix it. :(.

Try disabling Optimus in BIOS (under the video section) and seeing if that lets you see the POST screen

I can confirm this exact issue with the Dell G2410 monitors.  Unfortunalty changing Optimus and none of the new BIOS have resolved the problem.  This is espically frustrating for me because we use a whole disk encryption app so if you use your E6420 in conjunction with the problem monitor you can't see the login screen while docked.  Not to mention access BIOS or any of the advanced boot menus.

The Dell G2410's are the main offender that we have.  We have contacted support but gotten no where on the issue.

The problem apears to be the refresh rate that comes out of the dock monitor ports during POST.  If you are lucky you can catch the out of range message on the monitor or a diffrent model that works correctly.  It should say the signal is 61Hz which the G2410's can't display.  All of the ports exibit the same issue, DVI, DP, VGA.  No video during post makes typing a long complex password blind a real hassle.

I have updated my Dell Latitude E5420 to BIOS A09 and well I was curious whether this issue is still there. And to my surprise it is not (confirmed from my side that I still had ith with A07, did not try A08, went directly from A07 over A08 to A09).

Great, I can now boot up the system with the cover lid closed and I see the login screen over the DVI cable on my external monitor. Should also work with DisplayPort, yet I have not tried this yet.

Finally, Dell has fixed this really annoying issue and I am able to use my docking solution as it was intended to be used. Although, the fix is not even mentioned in their change log for BIOS A09 (very strange as if they were ashamed of this and didn't even wanted to get the attention that this simple issue could not have been fixed before).

I have also left my comment in this forum thread (same issue, different header): en.community.dell.com/.../20122333.aspx