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Windown 7 Dual Display with KVM switch video resolution issue

    Domanda

  • I have 3 HP desktop machines (2 XW8200, 1 XW8400) with Nvdia Quadro NVS dual-DVI display cards.  They are all going through a BlackBox KVM 4-port switch.  I have two HP ZR24W monitors.  All machines are running Windows 7 Enterprise 64bit.

    Everything has been working perfectly for a year or so, until I ran Windows Update on them.   I didn't have automatic updates set up, but my wife updated one because she saw the little balloon whining about it.  Another one was a re-install with updates automatically configured.  The third one got updated because for  whatever reason, I thought it needed it.

    One by one, as Windows Update was run on them, they've gone to a state where one monitor functions normally, and the other is shown as "Generic Non-PP Monitor" with the resolution capped at 1024x768. 

    The video drivers are up-to-date.  If I try un-installing the video drivers, I get a default of 800x600x16, which is unusable.

    Windows is 100% up-to-date (which is probably part of the problem)

    I've tried using different a KVM (Black Box 2-port) switch to no avail.

    If I connect the PC to the monitors directly, they work fine.  So there's some issue with how windows "sees" the monitor through te KVM switch.

    To characterize Black Box support as 'un-helpful' would be charitable.

    So in conclusion, I have 3 nearly identical machines all exhibiting the exact same problem: one monitor is restricted to 1024 x 768.

    Where do I go from here?  I'm convinced it was something that was updated by Windows, but I have no idea what update I would back out.

    domenica 26 febbraio 2012 20:03

Risposte

  • This is not a Windows issue. The behaviors are caused by the hardware. Try to upgrade the video drivers. If the issue persists, contact the hardware vendors to report this error.


    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. ”

    martedì 28 febbraio 2012 07:41
    Moderatore

Tutte le risposte

  • Is it possible a display driver was installed?  Microsoft occasionally delivers display drivers via Windows Update that have been through their WHQL process, but they're usually pretty far out of date by comparison to the display drivers that you can get directly from the web site of the video card maker...  Thing is, display driver development to this day is proceeding at a feverish pitch.

    It might be helpful to go to the web site of the maker(s) of your video card(s) and try installing their very latest release.

     

    -Noel


    Detailed how-to in my new eBook: Configure The Windows 7 "To Work" Options

    lunedì 27 febbraio 2012 19:14
  • I quadruple-checked - I'm as current as I can be with regards to the video drivers.
    martedì 28 febbraio 2012 01:30
  • This is not a Windows issue. The behaviors are caused by the hardware. Try to upgrade the video drivers. If the issue persists, contact the hardware vendors to report this error.


    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. ”

    martedì 28 febbraio 2012 07:41
    Moderatore
  • You mentioned video card drivers, but did you download/install the correct monitor driver (momentarily ignoring that it used to work without a monitor specific driver...  or perhaps it's 'not supported', see if there's a specific driver for your monitor. 

    So if you haven't already, find the driver, go to your screen resolution settings, highlight the monitor, click Advanced settings, and without auto-detect, see if you can install the monitor driver.

    Also (just keeping an open mind), perhaps damage to a cable? Maybe one from the KVM to the monitor, or from the PC to the KVM, but NOT the one you tried when you tried connecting directly from the computer to the monitors?

    martedì 28 febbraio 2012 21:22