Persistent horizontal lines appear on iMac screen

@jot hey - here is how:

1. I used the normal support channels, to speak to the support through chat
2. In the chat conversions, I requested to be transferred to a senior representative regarding a special situation that I need the highest level to be able to help me.
3. I was then scheduled a call with a "senior representative who I Katherine"

Key points:

1. I kept doing forgiveness work, releasing apple and the situation and I became willing to let it go if they are not willing - so I wasn't coming from an angry voice tone, but from a calm, and genuine voice tone of wanting to fix this together
2. I made sure I am being calm and I expressed gratitude to apple and told her how I spent over 7K in the past year alone,
3. She already had seen this thread and she knew and agreed something is not right.

Realizing Apple is a multi-billion dollar company and they really do stand behind their product, now there is enough evidence here for them to help those of us in need.

Dear Alok Mishra,

According to someone, apparently, the problem lies in a cable that also powers the LCD.

This cable (of the FFC/FPC type or Flat Flexible Cable / Flexible Printed Circuit), has to sustain a very high voltage (around 50V) to power the LCD.

After a while (in this case after about 2 years) it starts to burn out and degrade at the connector side, to the point where it lets the signals leak between the various connectors and short-circuits some of them, which ends up causing those lines that we are all unfortunately familiar with.

The "ghost" we see is the signal bleeding from one line to the other due to the short circuits caused by the heating and cable degradation.

That was explained to me by someone who is a technician. But because I'm not a technician, the explanation may not be 100% precise. But I think it's quite accurate and clearly points to a hardware fault.

Hey guys,

I posted here a few months ago about my problem, same way as yours, on an iMac M1. Started in august, in December the situation worsened, and in February, beyond the lines, the screen started to get VERY hot. During this time, I contacted Apple several times to report what was happening, even though they refused to repair it. I took photos and videos and documented everything, talked about this discussion and other reports. The situation only changed when I reported that the screen was getting very hot and was passed to a senior support and after a few days took the display for evaluation. It took about six months, many contacts, persistence and patience, two in-person evaluations, and luck to be served by attentive people. But it worked out: in March, I was informed that they granted me an exception (they emphasized this point) and approved the replacement of the display free of charge. I don't know if it was luck, the way things work in Brazil and customer service, or some genuine concern for customers, but it worked out. Keep reporting. I don't know if the feedback really works, but maybe talking to people will. Good luck!

haixin512 wrote:

Keeping contact apple feedback with the info below: (i do it once a week now)

Product Feedback - Apple

+1 It is a good idea to keep sending feedback and to call.

The kicker here is, that Apple does not make the display panels. They out source the display panels from third-party suppliers like Samsung, LG and others.

As I recall, something similar happen to some displays panels in the late 2005 and early 2006 iMac's. After a couple of years, some of the display panels starting getting multiplying vertical lines. Sadly it took Apple another year to settle-up with the display manufacture and acquire enough replacement displays to start an Extended Service program.

my problem was the same as yours, except for the overheating location (mine was at the top of the display). only when I reported the overheating that almost burned my finger, their attention changed. after that, they transferred me to senior support. I took pictures of my finger (it was superficial, but it happened), showed the overheating area, made videos showing the heating location and how the lines flashed more intensely at these moments. It took some time and two in-person evaluations, but it worked. they made an exception, and i had the display repaired free of charge.

Hi, I just want to thank you all in this post, because you helped me save A LOT. I had the same issue with my iMac 24" (late 2021), as shown in image below, and after 2 attempts calling to Apple, I was gifted with the free replace of my screen. I'm in Brazil, and here, replacement parts are more expensive yet, so, it was awesome. What I did:

1) First attempt > After going to an Apple authorized service, and be notified that I just had one thing to do (replace the entire display), I called to Apple and had a long conversation with an assistant, and he said to me that Apple doesn't give free displays like that, and also asked me to report the authorized center who did this. From this call, they gave me a link where I could upload photos and videos of the malfunction. No response and nothing happened for a week.

2) Second attempt (1 week later) > I went to another Apple authorized partner to get a new quote. In this partner, the same thing > no repair, buy a new expensive display. I left my iMac to repair, and was about to shut up and pay. But, in this very day, I read this post again, went to the Apple chat and there they escalated me to a Senior representative, who called me and saw that I had already filed a complaint and that this was the second time I was trying. So, this incredible and very kind representative (Roberta), asked me to report the problem and send the most recent quote for the repair. Ater 40 minutes, she came back with good news and said that I was eligible for the free repair, and she reached the service provider to "make an exception" (her words) to repair my screen for free, and that this "exception" will happen only once.

So, my advice is that you try one more time. In my case, it worked! I hope you can have yours fixed as well. And that Apple check this issue, because it seems to be a repeated question with many users. I never had problems with my mac devices, this is the first one. Thanks a lot.

Have you blown the dust out of the intakes lately?

What temperatures does this App report? Especially the GPU.

This App can be used to speed up the fans, all my iMacs would be dead without it.

Never ever ever drop fan speeds below the speed that the Mac itself is calling for.

MacFansControl…

https://www.crystalidea.com/macs-fan-control

One way you can prove or disprove that's its hardware or software is to erase the drive and install a new system. Do not migrate your user data to it for this test. If the problem appears then it's hardware and not 3rd party software issue.

If gone then it's software and you should manually restore the contents of your Music, Pictures, Documents and Desktop folders from your latest Time Machine backup to the new user account (which should be an admin account and can be your original user name and password.

Then you should reinstall all of your 3rd party software. NOTE: be sure to note all of the activation codes for those 3rd party apps that require them.

Also do not installed and run any "cleaning", "optimizing", "speed-up", anti-virus or VPN apps on your Mac on your new installation. A VPN is OK if it's required by your employer, bank or school.

If it's hardware related you'll have to make a decision as to how to address it. A possible alternative is to get an inexpensive 27 inch monitor and run it along with the damaged monitor and use it as your primary monitor.

Just some food for thought.

Addendum: all of this requires you to have a full and current backup of your boot drive with Time Machine or some other backup app.

If there ever is a fix it will be announced here: Apple Service Programs - Apple Support

So make a bookmark of that site and check it frequently. Also anyone who has this problem and has not taken it into an Apple Genius bar should so they know the extent of the problem.

I have this issue, M1 iMac purchased in Tokyo, Japan in 2022. It seems to be a problem in Asian countries mostly. I was working on a simple Google Doc, rubbed my eyes, and when I looked again the black lines appeared. Right in the center third of the screen. It's extremely annoying. And of course I don't have Apple Care...

This has been a noted issue on the iFixit site:

****

It does not actually seem to be that difficult to replace the screen. Has anyone tried to replace the screen themselves? There are a number of videos on YouTube for this: https://www.youtube.com/watch?v=uBjMr--idKo

But I'm wondering if I should just get an external monitor instead. It's very frustrating. I've been bragging to my friends about this M1 iMac for years now. "Buy a Mac," I say. "They're pricey but they'll last at least five years!" I am eating my words now. I have an M2 MacBook Pro that I also really like...am I going to have this problem with it in two years?

Apple, fix this. When people bring these 2021 M1 iMacs into the store, fix them for free. It's really lame to get just two years out of this computer, when it clearly can go for several more.

[Edited by Moderator]

MacBooks with FlexGate have similar problems. In the MacBook, this is caused by the LVDS cable, which is fixed to the PCB of the lcd assembly and not easily replaceable.

However, the LVDS cable in the iMac can be replaced. Has anyone had experience with this or replaced this cable before?https://www.ebay.nl/itm/255809013613?mkcid=16&mkevt=1&mkrid=1346-175129-2357-0&ssspo=9_Kc3GPRQIS&sssrc=4429486&ssuid=2ViFqcZVSqK&var=&widget_ver=artemis&media=COPY).

Hey everyone, when I got in touch with a senior advisor to escalate the case, they told me there was NO record of this being a widespread issue.

I asked if there’s a way for everyone experiencing this to report the problem directly, and the advisor pointed me to the Apple Feedback page. If you’re dealing with this too, I’d suggest submitting your feedback there. The more people report it, the better chance Apple might take notice and address it.

Hello everyone,

I’m adding my voice to the growing number of iMac M1 owners experiencing persistent horizontal lines across the display.

• My iMac is the 24-inch M1 (2021).
• The lines appeared suddenly and are worsening over time.
• When I connect to an external monitor, the issue does not appear, which suggests it’s a built-in display hardware fault and not a GPU/software issue.
• The lines do not appear when taking a screenshot, which suggest according to the apple advisor on the chat that it is a hardware and not a software issue
• I’ve seen many others here and on Reddit/MacRumors describing the exact same problem, often 1.5–2 years after purchase.

This seems to be a widespread defect, not accidental damage. It would be great if Apple could officially acknowledge this and provide support—whether through a repair program or extended coverage.

Has anyone here successfully escalated this with Apple Support and received a repair (in or out of warranty)? If so, could you share how you approached it?

Thanks for any advice, and I hope Apple is listening to the many of us dealing with the same display failure.

I'm doing exactly this now. Using a second monitor, and using the Lunar app to turn off the defective main display. Apart from the display, everything else is working as it should.