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macrumors 6502
Original poster
Jun 3, 2013

Note: I posted this Thread in MacOS Monterey Cathegory in this Forum - with no answers. So this is my 2nd try :-(

I have a strange Problem, wich i cant solve.

Setup: 27" iMac Late 2015 Base Model with 1 TB SSD @ Latest macOS Monterey
External Monitor: Dell Alienware AW3418DW

The external Display is connected via HDMI to Thunderbold 2 Cable.
Display works without any Problems.

If i shutdown the iMac or leave it in Standby the Display won`t turn on automatically (the external Display is not turned off and in Standby) if i start the Machine by pressing the Powerbutton on the iMac or - while in Standby - pressing Keys or move the Mouse the display remains black. I manually have to start the external Display and everything works fine. The iMac is not starting the display itself. Maybe its macOS related?!
I cant find anything regarding the Problem on the Internet. I tried different cables with no effect.

Any Help?

Thank you!
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