Persistent horizontal lines appear on iMac screen

I am reaching out to share an ongoing issue I, along with several other users, have been experiencing with our iMac 24-inch models, and to seek a collective resolution.


Problem Description:

  • Persistent horizontal lines appear on the screen, which significantly hampers the usability and visual appeal of the device.
  • This problem arises without any physical damage, and despite the stationary nature of the device.


Steps Taken:

  • Connected to an external display: The external display works fine, indicating the issue is with the iMac's internal display.
  • Reinstalled the OS: The problem persisted post reinstallation.
  • Avoided operating the iMac for a week: No change in the situation.


Concerns:

  • The cost of screen replacement is high, and there's no assurance that it will resolve the issue permanently.
  • The quality concern is alarming especially for a brand that positions itself as a premium segment player.
  • The support received thus far has been unsatisfactory, with no definitive solutions provided apart from a costly screen replacement suggestion.





Please do not ask us to visit to service center and replace the screen for 650USD + , problem happens mostly after warranty.


[Edited by Moderator]

iMac (M1, 2021)

Posted on Oct 21, 2023 10:40 AM

Reply
Question marked as Top-ranking reply

Posted on Jul 10, 2025 3:32 AM

UPDATE


I faced an overheating issue in the top right corner of my 2021 M1 iMac 24”, which eventually led to display failure with burn marks and a smoke smell after 2.5 years of usage. Initially, Apple India denied free repair as the device was out of warranty and offered only paid service. I escalated the case to Apple USA with proof that this was a known horizontal lines issue (widely reported in forums and media) and highlighted the severe safety threat to my family. After sharing high-resolution photos, videos, and diagnosis reports, and insisting on escalation to their engineering team, Apple granted me a one-time exception (CS Code) for a free display replacement. 🙏 After 90 days of usage with the new display, it is working completely fine, and I sincerely thank Apple for their credibility and for standing by their customers in critical situations.




Similar questions

521 replies

Feb 19, 2025 6:09 AM in response to 266aline

I had the same problem. There’s a burn mark on the rim of my screen.


My screen blacked out after 3 weeks and I’ve already turned the brightness to minimum.


I will suggest you to use a dual screen with the second screen set to mirror the first screen now.


Sent feedback to Apple and talked to Apple Support a couple of times but the only answer I got was full price repair or live with the problem. So frustrating.



Oct 28, 2025 8:06 AM in response to latVm

I wrote in one more time:

"One of my iMacs now shows horizontal lines across the lower display. Apple Store said it’s a hardware problem needing a costly screen replacement. Support later told me it’s just an expense after three years. That’s unacceptable. I’ve since found over 700 users reporting the same issue, likely tied to the iMac’s design and brightness management. As a loyal Mac user for 35 years, owning more than 22 Macs, I expect Apple to take responsibility. Please issue a repair or recall—loyal customers shouldn’t bear the cost of a widespread defect."

Fingers crossed.

If this is happening to you too, speak up. Write in the forum. We need to get Apple to accept the design flaw and cover the replacement.

Oct 30, 2025 1:06 AM in response to retroworldnews

Given a 100% fail rate (same display issue) of my four M1 iMac computers, I am pretty sure this is a wide spread issue. As all M1, M3 and M4 iMacs are having about the same design, I'd expect there will be increasing number of similar cases.


Nonetheless, I don't think Apple will admit the issue due to cost and reputation concern. Granting a Service Program means Apple admitting a design flaw in Apple chip iMac series. More importantly, it also means it admits the flaw was not addressed for a few years.


Although Apple will refund the repair cost if a Service Program is issued, but I think many affected users will just look for other solutions (e.g. connect to external monitor, switch to Mac mini).


I guess Apple will just change the circuit design in next generations of iMac, but it will not grant a Service Program soon. It may grant a Service Program after most affected users disposed their affected iMacs, so as to minimize the P&L impact, yet claiming its' goodwill in customer service.

Dec 19, 2023 5:19 AM in response to latVm

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.

Persistent horizontal lines appear on iMac screen

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