Persistent horizontal lines appear on iMac screen

Same issue here with an iMac M1 purchased in late 2021 in Japan. The problem started at about the three-year mark, with half the display obscured by thin horizontal lines (sometimes horizontal and vertical) flickering on and off. Thanks to the information and feedback provided in this thread, it seems well-documented as a parts failure. This is the second problem with an iMac display, but this time I’m still covered by AppleCare+. I’ll be contacting Apple and will report back hopefully with a resolution.

I'm Glad that they re-open the thread. Congrats @latVm

Anyway, I spent almost an hour on support, and even got a call from a supervisor, and he read al the forums, and acknowledged my issue, but there was no plan from Apple to solve it or to make any discount or exception on a new screen.

I had to take it and pay for a new screen, so, the costo of almost a new device.

I have the same problem. Purchased the M1 IMac 24 inch in Jan 2022. About 2.5 years into purchase, lines started from on the bottom of the screen and the box of lines would move up to the center of the screen and would flicker sometimes. This computer was 2K so I did not think I would have these issues 2 years after purchase. Currently the screen has turned dark and I cannot see anything at all.

This problem is limited to the M1 24" iMacs. However if you decide to go the replacement route you might consider what I did: got an Mac Mini M4 with a external monitor.

I go the M4 with 16 GB of RAM and a 1 TB drive for $999. The monitor I got is a 32" LG 4K monitor with speakers for $331. If you can live either the minimal Mac Mini speaker you can take about $100 off the price or go with a 27" monitor. A similarly configured 24" iMa is $1900 or about $500 more than the mini.

Just some food for thought.

I contacted Apple Support after the Apple Store Genius Bar told me they couldn't do anything other than replace the screen for $700. The support person acted like I was wasting his time because it was past the one year warranty. I told him I was aware that it was past warranty and mentioned this thread as evidence that this was a widespread issue due to a manufacturing defect rather than a problem that surfaced due to my use of the iMac. I asked him if I could talk to his supervisor for the purposes of escalating the issue. He got concerned that I was trying to get him in trouble and so I reiterated to him that the reason for the escalation was that I acknowledged that he may not have the power to make an exception to allow me to have my repair paid for. He finally agreed but I could tell that he still thought I was wasting his time.

His supervisor took his side, which I hope means that he's in great hands as a workplace. But from my customer point of view, he seemed like he was trying to get rid of me. He did not want to acknowledge that this issue was a real documented issue, and told me that I should just make sure I updated the operating system and that the problem would most likely go away if I did that. At that point I gave up.

Some details: I've started experiencing this issue since yesterday. Fortunately for me, right now it's just one horizontal, 1-pixel-thick black line near the bottom of my screen, which sometimes turns into multiple flickering lines (this happens when the brightness goes up, I think. I have turned off the auto-brightness and am using my iMac at low brightness as I'm not willing to test this hypothesis). I bought my M1 iMac in June of 2021, immediately after it was released here in India. It's a lightly used machine without a single scratch.

As I mentioned earlier, I kind of know what led up to this issue in my case. I recently updated my iMac to Sequoia 15.0.1. I usually never update to a new OS this early. Then, the night before the display issue, I was checking out the animated/dynamic screen-savers/wallpapers from Apple (I haven't checked them out before, so I was curious). A few minutes later my machine hung up and I had to force shut down by long-pressing the power button. I didn't think much about it and went to sleep. The next day, as I booted my iMac, I started seeing the line.

[Edited by Moderator]

I spent a couple of days talking to Apple support and taking my Mac to an Apple store. The Apple support person said that he could not help me with this as my device was out of warranty (I did mention about this thread to him). I did not get an answer on how to stop this issue from getting worse. The price quoted to me to replace the screen is Rs.60000, or about $700 USD.

From what I’ve seen here in the Apple Community, continuing to use the iMac despite these issues may not just result in a gradual worsening of the lines, but it could potentially lead to more significant problems. For example, there are reports in this very thread of a user experiencing a complete screen blackout, and another who mentioned a burn mark appearing on the edge of their monitor. While it might seem manageable now, it’s worth considering that these defects could escalate, potentially leading to more severe consequences. If possible, it might be a good idea to address the issue proactively.

Thanks to the tips posted by VanCitySean on Jun 22, 2024 at 9:40 AM, I was able to get a free replacement from Apple Japan. 

As that post was so helpful and encouraging to me, I am going to post a translated version on a Japanese Apple Support Community page. There is a thread starter facing this same problem and seeking advice on how to get their iMac throughly inspected. (The thread starter took it to an Apple authorized Service Provider, but didn’t get a satisfactory response and was simply offered a paid repair.)

I don’t know if VanCitySean will notice my message, but I'd like to express my sincere appreciation to you. You are the best!

I have two 2021 M1 iMacs having the same issue after +3 years of use. Genius bar offer a US$700 expensive repair option, which I refused to accept. Given my own experience and the threads I read so far, I believe this is a systematic issue rather than an isolated one. As a loyal Apple user, it is sad that it does not seem Apple is taking care of this issue seriously.

[Edited by Moderator]

It's unfortunate that this situation keeps happening. According to previous threads, this is a uniquely Apple issue across multiple products such as the laptops since 2001. It's honestly quite shocking that this issue still hasn't been fixed and honestly, I'm quite disappointed with the quality and lifespan of such a luxury product. Have been a loyal fan since I converted from Android devices, but cases like this makes me think twice.

I have the same problem, M1 2021

Apple refused to replace..it’s definitely a manufacturing defect and they don’t seem to be releasing a service program! Given that we spend so much money on apple products they want half the value of the machine for a manufacturing defect! Disappointed!

The advice I got from the Apple store in Leawood, Kansas is to buy a Mac Mini and new monitor. They said that the trade-in value for my computer is $0. Apparently, there haven't been enough reports of this problem for them to deem this a manufacturing flaw and offer a solution to its customers.

So I took the computer to the local Apple Service provider and they are charging $921 USD... yes.. NINE HUNDRED AND TWENTY ONE... basically more than a new imac mini.. So i just called Apple Support.. and same story.. you have to pay for the new display... THIS IS BAD, this when this thing pops up it's going to be a mess for them.. this is clearly a design problem that they did and we have to pay for. DO NOT buy an iMac until they assure they are going to fix this issue, your mac could fail at any time and there is no waranty that even if you fix it, it wont happen again. My guess is that Apple is not talking about it becase there are too many iMacs around, and it will be impossible for them to recall or to do free repais. This is bad, very bad.. it really makes me thing about investing my money in Apple products if they are not responsable for their mistakes.

I also have this problem, 14 months old. It happened suddenly in the middle of the day.

It's not really useable now. It's a defect with the screen, I used a secondary display, my TV and it looks fine.

[Edited by Moderator]