User profile for user: gaius777
gaius777 Author
User level: Level 1
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External display connected via HDMI and USB-C adapter to iMac suddenly does not work

I've had an external monitor connected to iMac via HDMI and USB-C adapter for several months. It functions as an extended display. Somehow the display went blank about 2-3 days ago and it seems the iMac now does not detect the external display.


I have tried using 2 other HDMI cables and another USB-C adapter, and the external display remains undetected.


Can anyone suggest how to troubleshoot and fix this, please? Thanks.

iMac

Posted on Sep 25, 2022 2:48 AM

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User profile for user: den.thed
den.thed
User level: Level 10
85,402 points

Posted on Sep 25, 2022 10:18 AM

Try resetting the iMac’s SMC and NVRAM.

see> Reset the SMC of your Mac - Apple Support

and > Reset NVRAM on your Mac - Apple Support

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User profile for user: gaius777
gaius777 Author
User level: Level 1
4 points

Sep 25, 2022 6:12 PM in response to den.thed

Thank you, den.thed!

Resetting the SMC worked.


I did the following from the link you provided:

"If your Mac isn't a notebook computer, follow these steps:

    1. Shut down your Mac, then unplug the power cord.
    2. Wait 15 seconds, then plug the power cord back in.
    3. Wait 5 seconds, then press the power button to turn on your Mac."


The external display is back in service... appreciate the advice.


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External display connected via HDMI and USB-C adapter to iMac suddenly does not work

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