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vincentwu800 Author

Level 1

4 points

iMac not detecting external display

Hi,

My iMac 27" (2019 version) can't detect the external display (hp 27" 2K monitor) after an accidental power shut down (I accidentally unplug the power).

After the reboot, everything is find, except that the iMac can't detect the monitor anymore. I've changed the monitor, the same. I've attached the HP monitor to my macbook, it worked too. So it's not the minitor's issue.

I've also recently updated the MacOS to Catalina, just in case there is any connection there. But right after the OS update, I could still use the external monitor. So probably not related.

Please help me! thanks

iMac 27", macOS 10.15

Posted on Nov 15, 2019 5:10 PM

Top-ranking reply

rkaufmann87

Level 10

144,862 points

Posted on Nov 15, 2019 6:36 PM

Please try resetting the NVRAM per the directions in How to reset NVRAM on your Mac and then re-test.

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iMac not detecting external display

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