External Monitor Not Recognized

When I start up my iMac, I am greeted with the screen flashing on and off. I have to restart to get the second monitor to come up with the desktop. This just started, and I have had this monitor for years. I recently upgraded to the last version of High Sierra, but that has been awhile. This behaviour just started.

Ideas...?

Posted on Mar 29, 2019 10:30 AM

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1 reply

Mar 29, 2019 12:06 PM in response to Charles Hess

Sounds like the monitor is failing.

Get help with video issues on external displays connected to your Mac

https://support.apple.com/en-us/HT201177

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External Monitor Not Recognized

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