tbuchalski
Level 1 (0 points)

Q: My MacBook Pro has stopped detecting my 40" Samsung Plasma HDTV.

I've tried basic troubleshooting, like powering down my computer and TV - and unplugging the TV - and then powering both back on with the cable connected. None of the basics seem to work. I think the settings on my computer may have been inadvertently changed when I closed my MacBook Pro whilst watching a video to cause this, but I do not know how to check this or change it back. Detect Displays in system preferences - displays does not work. I have yet to reset the PRAM and the SMC, but I'm noticing in my research that this doesn't always work. Any other working solutions out there to this problem, or am I doomed to be without video on my TV?

MacBook Pro, OS X Mavericks (10.9.1)

Posted on Sep 30, 2014 8:05 AM

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tbuchalski

Q: My MacBook Pro has stopped detecting my 40" Samsung Plasma HDTV.

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  • by alex_h1,

    alex_h1 alex_h1 Oct 2, 2014 12:24 PM in response to tbuchalski
    Community Specialists
    Oct 2, 2014 12:24 PM in response to tbuchalski

    Hello tbuchalski,

     

    Thanks for using Apple Support Communities.

     

    To troubleshoot this issue where you don't see a signal on an external monitor please follow the steps below.

     

    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.

    Using Closed lid, Extended Desktop, or Mirroring display modes

    When using multiple displays, information can be presented in a number of ways. For more information and what modes are supported by your Apple product refer to:

     

     

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

     

    Take care,

    Alex H.