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iMac as monitor - brightness stuck to zero

Hi there,


I'm using an iMac 2013 with target display mode for a Macbook pro 2018.

I have the thunderbolt 3 to thunderbolt 2 adapter, and everything works fine expect...


sometime, at random, the imac screen turn "almost" black. I notice the screen is not off, and if I move something around (from the macbook) I can see a faint shadow of a window. So connection is working. Is seems like the brightness is stuck to zero, for some reason.


I tryed to unplug and replug and it came back to life, but now it's stuck like this without recovering.


Also, i read the speaker should get the imput from mac, but if I select iMac as sound output the sound is completely mute.



Any help?


thanks

iMac 27", macOS 10.15

Posted on May 15, 2020 2:46 AM

Reply
Question marked as Top-ranking reply

Posted on May 18, 2020 8:26 AM

On the Target Mac...


To find out if it's system wide or user specific, try this...


Open System Preferences>Users & Groups, unlock the lock, click on the little plus icon, make a new admin account, log out & into the new account.


Does it work in the new account?

6 replies

iMac as monitor - brightness stuck to zero

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