Persistent horizontal lines appear on iMac screen

I've got the same issue too, purchased my iMac in August 2021. The lines started appearing November last year, about 2 years after the purchase.

Brought my iMac to the apple store and yes they offered a screen replacement which cost about SGD$900+

decided to not go with it as the lines are only at the bottom of the screen, hoping it wouldn't spread even further.

As you can see from the pictures attached, the black horizontal lines started off very faint and fine, it got darker the very next day, then about a month later it spiked suddenly. The lines would often flicker on and off too.

I've read multiple forums and threads on why is this happening and it seems like the only solution is to get an external display (which I did and it was fine on the external display). It also seems that most people are experiencing it 2 years after getting their iMac, coincidence or no?

This situation has really made me loose trust in Apple's product.

Please investigate this.

Revised version of post removed by the moderators.

Update: I decided not to replace the display for $648.00 as I felt the imac might have other problems if this happened after only 30 months. I got an estimate of $105.00 on the Apple trade in page I paid about $1500.00 for. The questionnaire specifically asks if the monitor is fully functional, to which I answered no. That knocked the trade in value way down, to that $105.00 number.

I sent in the imac using the kit they sent. About a week later got an email notification that they revised my trade in amount to $0.00. The reason given was that the display was not fully functional, which is why I was trading it in the first place.

I never mishandled the mac, it is surge protected, and I've never broken a computer I own. My last imac lasted 7 years and I only replaced it for compatibility issues with new software/apps and internet compatibility.

I'll reattach the image of the imac I traded in for zero dollars here. Not only were there lines as you see, but they flashed like a strobe. And yes, I took it in to the genius bar where they said it was the display and the only options were using an external monitor or getting a new display for it at $648.00.

I just want to restate I was not satisfied with this experience.

Same issue here.

Model: Imac M1 24"

Purchased : July 2021

First appearance of the issue: 18 FEB 2024

No physical damage. No heavy use.

Steps taken so far:

1. Contacted MAC support. Followed below step as per them.

1.a Booted in safe mode to see if its driver/application problem. The black lines were still showing up in safe mode

1.b Reinstalled OS

1.c Ran Disk check utility on all volumes/disks

Sadly nothing solved. Finally apple support asked me to visit nearest service centre.

1. Service center charged 2500 INR for diagnostics.
2. Advised to replace scree which will cost 54000 INR.

Contacted local repair shot. (Not MAC authorised)

1. Gave quotation of 45000 INR and 3 months warranty.

My current observation.

1. I feel this is overheating issue. The top right corner feels very hot when touched (Anyone observed this?). The logic board is at bottom. what device is there at top right corner? The lines come and go.
2. I tried to check CPU/GPU/FANs temp/speed using Fanny/ SMCFan control both application unable to show CPU or GPU temperature. And both show FANs speed around 16-20K which is abnormal.

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The product is expensive. This is the first time I purchased apple product, thinking I will use this for at least next 7-8 years never thought the screen will go bad in merely in 2.5 years. The screen replacement cost is very high. I can buy a 2 4K monitors in that cost. Apple should look in to this as this issues seems to be happening with lot of users.

Thanks,

P...

TOO HOT TOO HANDLE

it’s not just happening to me too.

I bought mine in November 2021 and the same thing started happening April 2023.

I immediately made an appointment with the local local Apple service center here in the Philippines and left it with them for almost a week. They told me the same thing to have the display replaced at around US$800 with no guarantee that it would solve the problem. I did not have it replaced because of this.

I wasn’t aware that this thread regarding the display problem was already in the Apple community. Besides all of the symptoms that I’ve read in this thread, has anyone been in been experiencing heat coming from any part of the iMac body? Mine is at the upper right hand corner of my unit. In the beginning, I did start using an external display to be able to use the iMac, however, while I was cleaning the screen of my iMac, I noticed that that top right part was getting discolored and when I touched it, it was really too hot to touch, that it almost burned my finger.

So since this time in about May 2023, my iMac has been a fixture in the house and I haven’t been able to use it since then. Really hoping to see where how this will be handled, this is the first time any of my Apple devices stopped or couldn’t be used in just two years of use.🙏🏽

UPDATE:

Got in touch with Apple Support; they asked me to take the backup of the Mac and start it in safe mode. Since the issue continued, I reinstalled macOS (Sonoma 14.4.1), but the problem persists.

Then Apple Support asked me to book a reservation at the Apple Store for their technician to check the iMac. They couldn’t check the price estimated for the screen repair. Of course I don't have AppleCare.

I am getting an inexpensive Samsung 1080p monitor and an Amazon USB-C Digital AV Multiport Adapter. I’ll connect the external monitor and continue using the iMac with the lowest brightness.

Hi,

A bit of hope : my screen fixed himself 2 months later. I was using excell and the bugged lines were blinking when i was scrolling down. After some hours, the bugged lines entierly disappeared. But if the screen is turned off, the bugged lines comes back again. It seems the screen need to be warm to work well.

To fix it again, i open excell and let it on. I don't Know if it's the solution or not but doing it, it works... 😅

This bug happened since apple made their uggly and useless animated screensavers. I wonder if there can be a connexion.

Dear Luntzzz,

Our problem is definitely a hardware problem (with an FFC/FPC type cable). Apple has no solution other than to replace the entire LCD.

That's what's been happening.

The (very expensive) out-of-warranty repair has always been paid for by users (those who choose to fix it).

...With the happy exception of one case, already reported here on this forum, who managed to present his case to Apple and have his complaint (deservedly) recognized by Apple, even out of warranty, which provided a complete replacement of the LCD. Unfortunately, this has not yet happened with our other cases, even though they are the identical ones.

Your problem, given that you've fortunately solved it using only a spreadsheet, appears to be a software problem and not a hardware problem.

If it turns out to be the same problem as ours, I can guarantee it won't get any better. It will only get worse over time.

...And not even a Microsoft spreadsheet will help you... 😅

Olá, pessoal! Infelizmente, também estou passando por esse problema das listras pretas na tela do iMac M1. Adquiri o meu em 2023, usado, e agora, após pouco mais de um ano de uso, as listras começaram a aparecer, dificultando a visualização e o uso do computador. Levei para diagnóstico em uma assistência autorizada, que atestou não haver sinais de mau uso ou avarias no equipamento. A fonte também está em perfeito estado, o que indica possíveis defeitos de fabricação. Compartilho aqui o link com o meu relato completo para que possamos trocar informações e, quem sabe, buscar uma solução juntos.

Linhas Horizontais na Tela do iMac M1 - Comunidade da Apple

Hi, everyone! Unfortunately, I’m also dealing with the issue of black lines on my iMac M1 screen. I bought mine used in 2023, and now, after just over a year of use, these lines have started appearing, making it difficult to see and use the computer. I took it to an authorized service center for diagnosis, where they confirmed there were no signs of misuse or damage to the equipment. The power supply is also in perfect condition, which points to possible manufacturing defects. Here’s the link to my full report (in Portuguese): Linhas Horizontais na Tela do iMac M1 - Comunidade da Apple. Let’s exchange information and hopefully find a solution together.

SAME problem here. In August (2024) the first lines appeared at the bottom of the display, increasing in November and in December becoming the same as yours. Sometimes they decrease, sometimes they blink a lot and the lateral (exactly at the height of your lines) gets extremely hot, even burning my finger superficially when touching it. Looking at an open screen you can see that this area is exactly a meeting point of two flexible power supply cables for the display. I strongly believe that their overheating is the cause of the problem.

I have already sent a lot of feedbacks, spoken to support and still have not had any satisfactory answer because it is no longer covered by the warranty, which is extremely disappointing and seems to me to be a manufacturing problem.

Another "victim" of this problem here 👋🏻 Recently brought in my iMac M1 24" (four ports) to the Apple Orchard Store in Singapore to get it checked by the technician who confirmed a "display issue" requiring fixing by display replacement. Unfortunately for me this issue surfaced just three months after my AppleCare+ extended warranty lapsed earlier this year🫨, and I'd initially ignored it/lived with it as it didn't really affect my daily usage back then (with just a few horizontal black lines at the bottom of the screen).

Photos attached are taken recently when the black lines suddenly multiplied for no good reason and now appear right smack in the middle of the screen, obviously hindering proper usage and hence I contacted Apple Support to seek help for a waiver of the hefty repair costs quoted (approx SGD$1K)- especially as this seems to clearly be a manufacturing issue and not the user's fault?! i.e. no physical damage or mishandling of device; in fact my iMac has been well taken care of (and cherished lol)🥹 I mean, just by taking a look at this thread and a few others both on Apple forum and other external forums- the increasing (and considerable) number of user complaints and shared accounts of this issue over the recent couple years since the iMac M1's release in 2021.

Would very much like for Apple to address this issue with the iMac formally, to address grievances of users (and Apple fans sigh) worldwide PLUS offer a recovery program/solution please, without us having to bear additional repair costs unfairly.

Thank you🙏🏻.

[Edited by Moderator]

Although this is terrible happening to a small subset of users, it doesn't seem a large enough issue for Apple to do a Repair Program. If it was the number of posters on this would be in the thousands and thousands of post and reports... I wish I know what the threshold is for this particular M1 screen issue. I mean clearly it's a defective component from production thats causing this. Just keep calling Apple Support and not just posting here in community forum. Call Apple support and stay on top of your case submitted to them.

Had the same happen on my son's 2021 iMac, M1.

We're in Hong Kong.

I tried asking online if I could get the display replace for free or discount; got no answer, just led me to a conclusion the problem is as on this thread.

Took the iMac to an Apple store Genius Bar.

The engineer - genius - went through the steps; likewise a conclusion there's an issue with the display. I mentioned this thread; many others with this problem.

The engineer went and came back with a manager; I showed this thread, including a couple of people reporting getting displays fixed for free, or perhaps free replacement offered after a year.

But was told this problem hasn't really been seen in Hong Kong; and Apple has not escalated it to the level of issue that involves multiple items being called back for repairs/replacements.

As also on this thread, I was told that I could get the display repaired, but expensive of course - and I said I might simply get a cheaper display, while it seems Apple has a manufacturing issue with this iMac display, not great it hasn't made it beyond four years.

Interesting; maybe it's a coincidence soon after I posted, or the issue is not so very rare here in HK.

Hope that if you get a second monitor - which I plan to do - it's easy enough to use as a display by simply plugging it in, without needing to choose any settings that would require the original display.

I have posted in this thread, with same issue.

Just phoned Apple support in Hong Kong, asking that this issue be considered by management.

Also just submitted to feedback at: Feedback - Apple.com Website - Apple

Reply:

//We cannot respond to you personally, but please know that your message has been received and will be reviewed by the iMac Team. If we need to follow up with you on your ideas for improving the iMac, we will contact you directly.

We appreciate your assistance in making the iMac a great computer.//

• well, won't be helping iMac if the issue persists, and they don't respond about this rather common failing.