ttran93
Level 1 (0 points)

Q: Since updating the 10.9.5 OS, my Dell external monitor has problems.  I am using an Apple Thunderbolt DVI connector.

The problem can be getting snow, to a blurry picture.  This occurs randomly.  I sometimes am successful with unplugging and replugging it back it.  At least for a while then it occurs again.  Do others have the same problem?

MacBook Air, OS X Mavericks (10.9.5)

Posted on Oct 10, 2014 9:25 AM

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ttran93

Q: Since updating the 10.9.5 OS, my Dell external monitor has problems.  I am using an Apple Thunderbolt DVI connector.

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  • by Jason L,

    Jason L Jason L Oct 12, 2014 7:33 AM in response to ttran93
    Community Specialists
    Oct 12, 2014 7:33 AM in response to ttran93

    Hello ttran93,

     

    Welcome to Apple Support Communities.

     

    The article linked below provides a lot of great troubleshooting suggestions which will resolve most intermittent snow or image distortion issues, like the issue that you’ve described.

     

    Apple computers: Troubleshooting issues with video on internal or external displays

    No video or no signal, image distortion, "snow," or flickering

    Check connections

    When using an external display be sure to check the following:

    1. If you're using an Apple notebook, confirm the AC power cable or adapter is securely connected to the computer and the cable providing power to the display is also secure. It is always good to have your notebook connected to AC power when an external display is in use.
    2. Confirm display adapters are fully seated in their respective connections and that they are supported models and for the computer and display. Refer to these articles to assist you with adapter compatibility and further configuration information:
    3. Remove all display cable extenders, KVM switches, or other like devices and retest to determine if the issue is resolved.
    4. Try unplugging the video adapter or cable and then plug it back in.
    5. If more than one video adapter is in use (or "daisy-chained"), troubleshoot by using only one adapter.
      • Example: A mini DisplayPort to DVI adapter connected to a DVI to HDMI adapter is an unsupported configuration because there is a series of adapters in use.
    6. If available, try using a different display and or adapter (or use a different connector by using DVI instead of VGA, for instance).

     

    Reset the system

    You can reset the Mac's parameter RAM and SMC.

     

    Reset the resolution

    Start by resetting the Mac's parameter RAM. If the display does not come up, was previously set to an unsupported resolution, and still results in no video:

     

    1. Start up in Safe Mode.
    2. From the Apple () menu, choose System Preferences.
    3. Choose Displays from the View menu to open the preferences pane.
    4. Select any resolution and refresh rate that your display supports.
    5. Restart your computer.

     

    Cheers,

    -Jason

  • by ttran93,

    ttran93 ttran93 Oct 20, 2014 9:25 AM in response to Jason L
    Level 1 (0 points)
    Oct 20, 2014 9:25 AM in response to Jason L

    Hi Jason,

    I have confirmed trying all the above mentioned steps and did not get it resolved.

    1. AC cable is connected.

    2. I am using an Apple DVI to DisplayPort adaptor

    3. Done

    4. Done

    5. Only one display port is used, an the Display Port works

    6. I tried using another monitor and projector, both have the same issue

    7. I reset the PRAM and it seem to help for about an hour and went back to the same issue

    8. Resetting the resolution does not help

    9. I upgraded to Yosemite to see if the issue is fixed but was unsuccessful.  I Time Machine back to 10.9.5

     

    I am considering

    -Trying another adaptor in case mine is a defect

    -After researching online, it seems like the issue is software related. So reloading Mavericks 10.9.4 to see if it would fix the issue.

     

    Any other suggestions?  Thank you so much for your help.

     

    Thang

  • by Jason L,

    Jason L Jason L Oct 20, 2014 11:34 AM in response to ttran93
    Community Specialists
    Oct 20, 2014 11:34 AM in response to ttran93

    Thank you for using the Apple Support Community. Due to the nature of your issue or question you may find more information by using another one of Apple's support resources - https://getsupport.apple.com/GetproductgroupList.action.