Just bought a new iMac 24" and plugged in a Thunderbolt to HDMI cable to link up my Dell U2717D external monitor. Every few minutes the Dell goes black then comes back on after 3-4 seconds. I never saw this issue with my last iMac (2017). Any suggestions?
iMac 21.5″ 4K, macOS 13.1
Hello sosighatease,
To help resolve this issue, you can try using a different cable to see if it makes a difference. This will let you know if the cable is causing the issue. You can also try changing the refresh rate to see if this could be causing the screen to black out as shown in this article: Connect a display to your Mac - Apple Support
Configure display settings
• From the Apple menu in the corner of the screen, choose System Settings (or System Preferences), then click Displays. In display settings you can change display resolution, choose a refresh rate, arrange your displays, and more.
• If the display is not made by Apple, certain settings might be available only by using the display's built-in controls and menu system. Check your display's documentation for details.
This article provides additional information on the refresh rate:
Change the refresh rate on your MacBook Pro or Apple Pro Display XDR - Apple Support
Best Regards.
external monitor keeps shutting off and then coming back on
