Persistent horizontal lines appear on iMac screen

You're experiencing what many others are:

The following topics illustrate the Silicon M1 iMac Display problem:

Screen Failure on 24-inch-iMac, M1, 2021 - Apple Community

Persistent horizontal lines appear on iMac Screen - Apple Community

Horizontal Lines on Screen of iMac, 24", 2021

Horizontal black lines covering bottom 3rd of 2021 M1 iMac screen

Grey horizontal patches on my M1 iMac 2021 model

Horizontal lines at the bottom of iMac(M1,2021) screen

Horizontal Lines on 2001 M1 iMac Display

M1 iMac Display vertex heating to scorching 55°C  — Seeking Advice on Escalation

Horizontal Lines on iMAC with M1 chip

Currently there is no Service Program for that issue but keep checking this website in case Apple instigates one: Apple Service Programs - Apple Support.  

You have 3 options:

1 - have Apple repair the screen at a quoted price. 

2 - add a 3rd party monitor while darkening the iMac's screen.

3 - replace the iMac with a new M4 Mini: a 10 Core Mac Mini M4 with 16 GB RAM and 1 TB SSD ($999 + tax) with a 27" LG 4k monitor ($250 + tax from Amazon.com)  is $1249 + tax which is $560 less than a similarly configured new 24" iMac ($1799 + tax)  re 07/2025.  

I just got the above new Mini M4 with a 32" 4K LG monitor w/speakers (didn't realize the Mini came with a speaker). It was around $550 less than a. comparably configured new iMac.   You can always order more RAM, storage and cores in the CPU if needed.

Your part number ends with this?

• LL/A - the US and Canada

I am having the same problem. I've had this iMac less than two years. These lines appeared a couple weeks ago and have shifted a bit but haven't disappeared. From what I'm seeing online, we are not the only ones experiencing this. This is not right. Apple should be held accountable for this issue.

This is just the beginning. My iMac M1 started with some lines below, slowly filled up over the span of few months and eventually a black screen. If the problem is the quality of the product, a replacement will give you the problem again. Why are we bearing the cost of a product that is below par?

I’ve been having the very same problem for a very well maintained 24” iMac M1 purchased in July 2021. This is very clearly a manufacturing defect. There’s no reason for a lot of people to have this issue pop out of nowhere exactly 2 years later. How do we go about claiming manufacturing defect? Any advice would be valuable. Ain’t no way am I going to pay 600+ dollars for a defect that took only 2 years to pop up.

The exact same issue is happening to my iMac 2021. I purchased it new in December 2021 in Denpasar, Indonesia, and it has worked perfectly for 2 years. I have taken the utmost care of it - no damage at all.

Suddenly, the bottom half of the screen filled with horizontal black lines. This happened about a week ago, and they went away. It happened again once more, before disappearing. Now they are back and not disappearing after shutting down and turning on again.

I can't believe that it is a coincidence that it is happening to so many people almost exactly 2 years after purchase.

Apple, we need you to investigate this, and to deal with this fairly.

There are only going to be more and more people with this problem.

I have this problem also, the lines flicker with mine. It occured while I kept my computer stationary without moving it at all. It's clearly a defect with the display because it happens without a cause. Apple should offer a free fix to people who have these lines regardless of warranty status. I can't pay the 700$ currently and it's ruining my computing experience.

This must be a software issue, all these reports seem to have suddenly happened in a short period of time with machines the same age.. this is my wife’s iMac and it started while she was using it.. just suddenly popped up like it. Turned it off for 24 hours but still the same.

Exact same issue popped up on my 2021 M1 24" iMac this week. Purchased it back in April 2022, so a little under 2 years. I have it connected to a secondary monitor, which works fine. Only the main iMac display's showing this issue. Have also tried resetting the iMac which didn't work.

Have an appointment scheduled at the Genius Bar in Singapore tomorrow, which I plan to cancel. There's no point bringing my device there only to be told to pay upwards of $800 to get a screen replacement done when I can get a Mac mini for the same price. Everyone in my family is on the apple ecosystem, including MacBooks and Mac minis because because we trust in the quality of Apple products so this happening is just shocking.

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.🙏🏽

Just stumbled upon this thread. It happened to me today.

I can’t believe the similarities too - approx 2 years of use, abrupt development of vertical lines, scorching heat on top corner of the screen.

I called Apple support and asked if this was a common occurrence, and was told that they have gotten calls about it.

I think it would raise awareness around the issue if we called to report en masse.

800 186 1087 (toll-free, if anyone needs it).