M1 iMac Black lines on screen!

Question

Level 1

17 points

M1 iMac Black lines on screen!

I need some advice. Yesterday, I noticed some black lines on the underside of my M1 iMac. I used it an hour before and it didn't have the issue then. But when I returned, the lines where there and seem to flicker with is very distracting to me, especially due to my mental state. It's very annoying and im already started to hate my once loved iMac. I already filled in a feedback form to notify Apple so they can inspect the issue for later models. But I am disappointed in the quality of this product. Im not used to having to deal with these kinds of technical issues. That's why I buy apple and promote them to friends and family. I first thought it might be just my bad luck but reading the forums here and at fixit, make it seem that the problem is bigger. What to do next?

Posted on Jan 1, 2026 12:00 PM

Reply

Answer 1

Top-ranking reply

Smilin-Brian

Level 9

60,287 points

Jan 1, 2026 1:40 PM in response to Ivannetje

First, let’s see if this issue happens in Safe Mode:

Shut down your Mac.
Press and hold the power button on your Mac. As you continue to hold the power button, your Mac turns on and loads startup options. When you see Options, release the power button.
Select your startup disk. It's named Macintosh HD, unless you changed its name.
Press and hold the Shift key, then click the “Continue in Safe Mode” button below your startup disk.
Log in to your Mac. You might be asked to log in again.

If the strange behaviors do not occur, then it may possibly be a software issue.

If the issue doesn't continue in safe mode:

Leave safe mode by restarting your Mac normally, then try to reproduce the issue.

If the issue doesn't return, it might have been resolved by the other things that safe mode did at startup, such as checking your disk and clearing caches.

If the problem persists, then let’s try this:

If none of those ideas work, then I recommend service.

Service Checklist:

Click ▶︎ Start a Service Request. ⚛️

Need more help?

Click ▶︎ Check Repair Status. 🔧

Good luck! 👋🏼😉

Reply

Answer 2

Ivannetje Author

Level 1

17 points

Jan 1, 2026 3:09 PM in response to Smilin-Brian

Thank you for your time and assistance.

I’ve read your comment and did everything from it that i could do now but without any difference. The issue insists. I’m afraid it’s going to be a service request but the cost will be high. In the meantime, i read a lot of posts from people with the same issue. It bothers me that so many people seem to have this specific screen problem with their M1 imac. It seems like its some kind of flaw in the display ribbon cable that acts up on the iMac tier above base model. I also filled in feedback to inform apple about the issue. Hopefully they’ll do something with all those messages so future models wont have to deal with it.

Thanks again.

Reply

Answer 3

Jan 1, 2026 3:58 PM in response to Ivannetje

From my own personal experience with Apple products over the years, the best (most reliable) desktop I have ever owned was a Mac mini.

Smiliñ 😎 Brian

Reply