2024 M4 Screen Flicker, Tahoe 26.1

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Level 5

6,440 points

2024 M4 Screen Flicker, Tahoe 26.1

I have a 2024 iMac M4, running Tahoe 26.1 in which the screen is flickering. The machine is out of warranting in about six weeks. I've been trying to pay attention to if the screen is flickering within the Apps, especially Apple Mail, or it's the entire screen. As of this writing, to my eye, it seems within the apps vs the whole screen because I notice the flicker most when changing open windows, like Apple Mail.

Has anyone else been experiencing this with the M4. I know there are discussions about screen flicker which lead to horizontal lines with the M1.

Because of my warranty situation, if I made an appointment at the Genius Bar, would they be able to diagnose a screen issue such as this if one existed.

iMac 24″, macOS 26.1

Posted on Nov 22, 2025 4:50 AM

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Answer 1

Old Toad

Level 10

215,196 points

Nov 22, 2025 10:42 AM in response to Joe Gramm

Boy I miss read that entirely. Have been working in the Mini section a lot and forgot where I was. Another sign of getting old. 😔

Well now that I know what machine we're talking about I have some questions to ask the author:

Have you installed and run any "cleaning", "optimizing", "speed-up", anti-virus or VPN apps on your Mac?

Please download and run Etrecheck. The free version is sufficient.

Copy and paste the results into your reply. Etrecheck is a diagnostic tool that was developed by one of the most respected users here in the ASC to provide a snapshot of the system and help identify the more obvious culprits that can adversely affect a Mac's performance.

Copy the report

and after clicking on the Reply button use the Additional Text button to paste the report in your reply.

Then we can examine the report and see if we can determine the cause of the problem.

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Answer 2

Old Toad

Level 10

215,196 points

Nov 22, 2025 10:12 AM in response to Joe Gramm

Joe Gramm wrote:

if I made an appointment at the Genius Bar, would they be able to diagnose a screen issue such as this if one existed.

Yes, unless it's the monitor itself. What is the make and model of the monitor? Are you using the cable that came with it? What type of cable is it?

If the cable is an HDMI cable try getting an ultra high speed HDMI cable to try. You can always take it back if it doesn't fix the problem.

If it's a USB cable try getting a USB-C cable with a USB 3.2 Gen 2 or higher standard, supporting 10Gbps data transfer or higher and see if that helps.

When you take your Mini into the Genius Bar be sure to take your current cable so they can test it.

Also make sure you have a curren and full Time Machine backup of your Mini before you take it in. Appe will probably erase it, add the latest system on it and test to rule out any software that might be the cause. Then when you get back home ou can use Migration Assistant to get migrate your user data and setting from the backup to your Mini.

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Answer 3

Joe Gramm Author

Level 5

6,440 points

Nov 22, 2025 10:31 AM in response to Old Toad

Old Toad, It's an 2024 iMac M4, not Mac Mini. I should have made that clear in the title.

I'm using the power supply and built-in ethernet port that came with the M4 along with a cat 5e cable into an Arris Surfboard SB8200 cable modem. WiFi set up is an Amplifi Alien using the supplied cable back to the Modem.

The flicker is intermittent which could be a problem bringing it to the Genius Bar.

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