3 Replies Latest reply on Feb 28, 2010 6:35 PM by T.C.

    DH55TC: DVI not working correctly when HDMI connected

    brutus

      Hi all,

       

      I have 2 displays connected to my DH55TC. DVI as main display and HDMI for extension. I i boot the computer with HDMI connected, the windows boot animation is displayed on HDMI, the windows login sceen then appears on DVI. But this login screen has crudy resolution, so the DVI display isn't recognized correctly. If if boot up without HDMI everything is fine.

       

      Does this appear to you, too? Do you know anything to solve this issue?

      Do you know a way how to set the DVI as the "main" display?

       

      Thank you in advance!

        • 1. Re: DH55TC: DVI not working correctly when HDMI connected
          T.C.

          I think I may know the answer to that.  The DVI is only enabled for POST when there are no monitors attached.  If you have an HDMI and DVI connected, the POST should show up on the HDMI monitor.

           

          The DVI-D port supports digital DVI displays. The maximum supported resolution is

          1920 x 1200 at 60 Hz refresh (WUXGA). The DVI-D port is compliant with the DVI 1.0

          specification.

           

          The DVI-D port is only enabled for POST when there are no monitors attached to the

          VGA or HDMI connectors.

           

          The HDMI port is enabled for the POST whenever a monitor is attached, regardless of

          the VGA and DVI connector status.

           

           

          http://downloadmirror.intel.com/18505/eng/DH55TC_ProductGuide01_English.pdf

          Digital Visual Interface (DVI-D)

          • 2. Re: DH55TC: DVI not working correctly when HDMI connected
            brutus

            Hi T.C.,

             

            than you for your answer.So, it is right, that the HDMI is the primary display. Ok, although I think that having no chance to select the primary display is some kind of underdeveloped, I can live with that. I think this is an absolutely common use-case to use the HDMI only sometimes for TV having a DVI main display at the same time without need to swap cables every time.

             

            So, i'm using windows and need not to view the POST, it's enough to set the DVI to widows-primary so that login screen shows there. But THAT is the real problem:

            If if boot up with DVI and HDMI connected, the DVI signal is scrumbled. In windows, it shows an resolution of 1680x1050, but in reality the board puts something like 1669 x 1067 out. My DVI-TFT can't display this resolution without failure and i'm convinced that this behaviour is not ok. The only way to get this constellation work is to attach the HDMI _after_ POST.

             

            So, i will try to connect Display via VGA-Adapter and report results. Thank you!

            • 3. Re: DH55TC: DVI not working correctly when HDMI connected
              T.C.

              I agree.  It would take a programmer all about 5 minutes to put a setting in the BIOS for primary and secondary settings. The other issue you mention, it sounds like it's a bug.  I suggest contacting Intel Support and see where that goes.  I have reported requests for bug fixes in the past. Most of the time they tell me it's supposed to work that way and then when the next BIOS update or Video Driver update comes out, the issue is reported as fixed.  LOL!  So the thing is, if enough people notice the issue and it gets back to the programmers, it usually gets fixed.  Good luck.   I was actually looking at upgrading to the DH55TC board on my primary computer from my DG45ID.  I might wait on that.