Persistent horizontal lines appear on iMac screen

Sad to say Even they offer free repair on the screen, the lines problem will still come back upon using it for one year or so. FYI My is M3 iMac also encounter this flaws beside your M1. In fact I curious on those using M4. I don't feel shock their iMac after using it for one year or so , Lines suddenly appear on their screen. IF that happen means Apple Quality is indeed in Doubt since the flaws start from M1 now continue to M3....

I took another poster's suggestion to write to Tim Cook. I received a reply within a couple of hours from 'Brandi', a rep at Apple. I replied to the email restating my case and received a call today after I missed a VM. I spoke, pleaded, actually, stating my case (and those of the 740+ unique individuals who have posted in this forum or clicked "me too", asking for Apple to take responsibility for their problem causing the damaged screen. I was on the phone for about 24 minutes without result. She said she would set up a (another) call with a senior advisor and advocate for me.

To keep this short, I'm rethinking my 'blind' loyalty to Apple since becoming a customer with the Mac Classic in the early 1990s. I'd like to have a reason to remain a loyal user.

I am very disappointed with Apple for two reasons:

1. My 2021 iMac screen started displaying horizontal lines (and flashing) on the bottom half of the screen. Since so many others have also reported this problem, it speaks directly to the deficiency in this Apple product.
2. I traded it in for a Mac Mini last week. The trade-in value was estimated at $45. Today I got an email saying I had misrepresented the product and the new trade-in value was $0.. That is because I accidentally said that my machine had a 256GB SSD when it actually had a 512GB SSD!!!

This is just addding insult to injury. Apple should be ashamed of themselves.

Thanks for all this information which call to Apple Support provided none of when my iMac 2021 suddenly developed flickering horizontal lines on the screen when I turned it back on after shutting it down for a week while I was out of town. I have had it for 4 years sitting on my desk--no damage by me. For what it is worth, I found the "Product Feedback" page on Apple website and sent link to this thread, and wrote this about my defective iMac:

"https://discussions.apple.com/thread/255220596?sortBy=rank

I have joined the hundreds of iMac customers who have been burned by this defect as you will see in above thread. My family own Apple products since the 1980s, both at home and at work, for their quality, reliability and customer accountability. No longer it seems when a 4 year old iMac in pristine condition out of the blue develops flickering horizontal lines on all but the top of the screen. Talk about a headache. Apple's solution: buy a new $600+ screen (same design) with a 90 day warranty! Where is the investigation? Apple acknowledgement/help? The fix? Meanwhile until the hardware glitch is fixed: recalls, free or highly discounted screen/computer replacements. Our loss of $/time/energy/lost productivity is not small."

Only hope is protest of enough customers.

Thank you for participating in the Apple Support Community.

We want to make sure you reach the right team for help with your device. We recommend that you contact Apple Support directly. Depending on your region, you may be able to reach them here: Get Support.

Monday, December 1st suddenly the same horizontal lines appeared on the display of my iMac 24" M1 (2021).

1) One black fixed horizontal line on the middle of the display

2)During the evening, below this line there is a space of 5/6 cm with normal display and below this all black lines

3)During the day, the black lines reach up to the central black line and some time they are flickering

I'd like to point out that I always kept the display brightness low.

A Senior Advisor confirmed to me that it is a hardware problem and to report to Feedback - iMac - Apple

I am truly disappointed with this product and with Apple's continued failure to acknowledge a design flaw in this iMac.

I'm really angry when I think that my Mac Book Pro works perfectly after 10 years and I have no intention of spending 900 euros to repair the iMac to replace the display with only a 90 days warranty!

This is trully manufacture defect on screen designed because almost every user experienced it with same problem.

I don't know it will affect on iMAC M3 or M4 on the future and it's make me worry because right now I have M3 IMAC that I bought it at 2024 June.

I bought M3 IMAC because my M1 IMAC experience (2021 November) the same issued with persistent lines on screen on (2024 May) take a looked on my last post

Hi RobertoDQ.

Thanks for your explanation.

Are you aware that the same issue will very likely occur again with the display you purchased?

The fault lies in the display itself, not in the computer.

You mentioned that you “bought a new display on A##zon and replaced it myself; it cost around $350. It’s not difficult, but you need to be careful because some connectors can break if pulled too hard… The display is now working 100% fine.”

Would you be able to explain in more detail how you carried out that replacement?

A clear, step-by-step description of the procedure would be extremely helpful. Many people might consider following your guidance, or alternatively decide to entrust their iMac to a technician after understanding what the process involves.

A detailed explanation of the steps you took would be greatly appreciated.

It's a solution that isn't without some risk, but it is a solution, and someone else may be tempted to follow in your footsteps.

I am yet another user experiencing this issue. I spoke with an Apple Care Specialist and was encouraged to get the repair done by an authorized repair technician or company so that if the problem ever becomes a "Supported Repair Case" I can be reimbursed.

I am posting this here so that Apple has a chance to see that yet another user has been affected by their hardware issue.

stevenfromsan francisco wrote:

I am posting this here so that Apple has a chance to see that yet another user has been affected by their hardware issue.

If you want Apple to see something, post it here…

Feedback - macOS - Apple

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]

Doubt it helps, only " temp " I actually encounter recently from last year. As mention the flicker lines appear on Oct last year for me. Just after two years of usage. I never do anything " tweak " or go install what fan control software.

One day when I wake up the Mac, suddenly the lines seem gone. I feel wow what happen? It last till recently. Suddenly lines appear back and flickering this time. I noticed there are increase of lines. Still at the bottom. I remember is around close to Nov , suddenly the lines don't know why gone. I thought wow is " Magic ". So from Nov to dec , I never see the lines again. But I do know just " temp ".

Yeah and this lines is back just recently... I feel your tweak only Just temp. The lines surely come back just matter of time.. Again the main issues is the Hardware. I feel.

I payed €800 to fix the screen: the conclusion was that there was a very small crack in the lcd screen… ik works fine for now…

Do any of you have AppleCare to cover this issue? It's starting to look like these M1 iMacs are going to have screen issues within a year or 2.

If I was stuck in that position I'd go for an external Monitor. :(