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tnrgtr Author

Level 1

4 points

USB-C to HDMI display off and on, then disappears

I am using the USB-C connection on my 2019 iMac 21.5 with an HDMI cable connected to my Outlaw 976 preamp (which is connected to my 1080p TV). This results in intermittent screen flashing and eventually the iMac loses the HDMI connection entirely. For a short time I can see the display options which are to optimize the display for the Outlaw 976 or to scale at 1080p, 1080i, or 720p, and the same settings for the Retina display. I tried changing the setting from Outlaw optimized to one of the scaling options but it didn't help with keeping the connection stable.

iMac Line (2012 and Later)

Posted on Oct 22, 2021 7:55 AM

Top-ranking reply

D.I. Johnson

Level 7

24,173 points

Posted on Oct 22, 2021 8:17 AM

Start your troubleshooting by ensuring the quality of the cables and connections between the devices.

Remove the preamp from the equation. Does the iMac gain a stable connection with the TV?

Has this setup ever been trouble free?

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USB-C to HDMI display off and on, then disappears

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