Persistent horizontal lines appear on iMac screen

I can't remember which video i followed but pretty much all are the same, here is an example:

https://www.youtube.com/watch?v=uBjMr--idKo

There are several youtube videos that explain how to replace the imac M1 display that are pretty helpful... I remember that i just had to be very careful with the connections, some of them can break if you pull too hard, also take a look how they unhook so you do it the right way, the display I got included all the tools you need.

Some displays might not come with the camera (mine didn't) so you just have to remove it from the old display and place it back, be careful and take a good look how they are placed, some new glue could help, besides that, it's nothing complicated.

In order to get the display you can buy it form Am*zon or Eb@y, i got mine from Am*zon, one thing that happened after i updated the OS to Tahoe is that it recognized a new display so the computer performed a hardware check and that was it... iMac is working again.

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.

My local Apple dealer was charging me $900 in order to repair the screen, I ended up buying a new display at Amazon and replacing it by myself, it cost me around $350, is not hard but you have to be careful because there are some connectors that can be break if you rip them hard... Display is now working 100% fine ( for now ) .... Thank you Apple for nothing!

What i'm thinking is that Apple is well aware of this problem, but they will not recognize it because it will cost them TONS of money, also because this is a design problem, it will affect eventually other models that share the same design, M2, M3, etc, etc.. not just M1 and this will carry a huge lost for this product, there is no other reason why they are not assuming their responsability.

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

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!

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.

My Apple M1 24 Inch iMac, 2021 which was purchased in Nov 2022, is experiencing the same issue.

I'm in Brazil, and I have a 2021 iMac M1 that started showing horizontal lines in the lower left corner of the screen two days ago. Today, these lines, which were light gray, have become thick black lines and are flashing across the entire lower corner of the screen. One black line remains permanently visible, and the others flash every 1 or 2 seconds. I've already contacted customer service, and they suggested replacing the screen for R$ 6600.00. I've tried mirroring the screen, and the problem doesn't occur on my iPad. I've tried restarting, turning it off, and unplugging the power cord, but nothing solves the problem. I have more photos and videos of the problem if needed.

>> 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

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.

yes, i would of wanted to do this, however the upper right hand part of the imac gets extremely hot while its on. dont want to take the chance of it catching on fire while not being used.

Anyone experiencing the same thing?

Anyone with this issue should really call Apple Support directly. The support person will document the issue and Apple Engineers will see these reports. You can slo provide information on the product feedback page but calling them is the best method.

Make your voice heard here: https://www.imacusersvoice.com/

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.