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

Top-ranking reply

Limnos

Level 10

426,965 points

Posted on Feb 7, 2024 9:45 AM

To make the best of a bad situation you could always use a separate monitor with the iMac. It's an annoyance given that there's already a display taking up desk space but at least you wouldn't have to get another computer. I kept several older iMacs going that way. Just make sure that if the display is really starting to go that you set this up before it is fully gone. You set up the second display as mirroring the first one and with iMacs this has to be done while you can still navigate the main display.

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499 replies

Jasp79

Level 1

58 points

Jan 22, 2024 9:23 AM in response to cristobal2

That dit not work for me… the screen issue came back for 3 or 4 times during the last months… until at the end it dit not disapear at all. So, went to the Apple repair shop and had to buy a new lcd screen (€800)

Dec 4, 2025 7:16 PM in response to inyakz

Mine does the same thing. I told them I was concerned it had the potential to be a safety concern and they escalated as such but it was a no go. I burnt my hand on it. They literally told me if it did happen to catch something on fire they would not be liable. Absolutely ridiculous.

-g

Level 4

3,365 points

Dec 4, 2025 7:46 PM in response to LizEnserink

>> LizEnserink

>>They literally told me if it did happen to catch something on fire they would not be liable.

much more serious than ridiculous -- i hope you got their employee info -- confirm that advice is quoted in your case notes -- you got a case number (i hope) -- i would call again tomorrow, reference your case number, insist that your notes are up to date (have them read them back to you) -- that call should be logged in any case -- get a screenshot off your Recent Calls to document...

it seems reasonable that you speak to a supervisor over that advice -- i would -- get a confirmed case number and accurate case notes logged -- good luck

Dec 11, 2025 8:58 PM in response to latVm

Our Upgraded iMac (24-inch, M1, 2021, 16/512 , 4 ports - yellow ) developed persistent horizontal lines after OS update. we contacted Apple India support and requested for one-time exception towards repair charges as it’s out of warranty. we submitted device at service centre in Hyderabad India.

After one week Apple denied for exception and said it’s paid service. we couldn’t afford the repair cost so decided to take back the device. service team collected INR 3708.00 towards diagnosis and adhesive charges and returned iMac. they said Apple asked for internal diagnosis so they opened the front glass and fused it back with adhesive.

After bringing device home when we turned on it worked fine for sometime . all of sudden there was smoke from bottom and showed vertical orange bars while turning off. we escalated issue to Apple USA support and they assigned it to India safety team. This time a senior engineer handled the case. after two days India Apple support again denied request for any exception towards repair or replacement. though this is widely reported issue worldwide with this model Apple India didn’t consider our pleads and we are left helpless.

[Edited by Moderator]

Persistent horizontal lines appear on iMac screen