Persistent horizontal lines appear on iMac screen

May I know what you said to customer service? I just had this problem, and now I can't afford to pay $700 to replace the screen

my imac(m1) have this problem too, so bad

hello!

i have exactly the same issue since yesterday, I bought my imac (24 inch, M1, 2021) on 5March 2022 and yesterday I experienced these color lines while I left my computer on for awhile… I just bought it for less than 3 years??? and I am still covered under warranty, I am afraid that after repair the same issue is going to come back up again….

latVm wrote:

Lol free diagnostic? They charged ne 30USD for inspection

Where are you located? as stumpy1946 pointed out in the US at the Apple Genius Bar the diagnostic is free. If you go to an Apple Authorized Service Provider they may charge you for the diagnostics but wave it if you have the repairs done there.

Update: The horizontal black line disappeared, turned it off for a few days after but when I turned it on it was still there, a few hours after, I thought it disappeared by itself, but it just moved to the left part of my screen and became a vertical yellow line. Starting from where the horizontal line appeared the last time down to the bottom. Up to now, the vertical line is still there. It's unnoticeable, better than the irritating horizontal black line.

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

I have exactly the same issue. lines appearing, then after shutdown was not there then appear again. Another shutdown next restart lines are not there. Now lines appear again and always appearing even after shuttingdown for weeks.

Good point. I always get AppleCare on all my Apple devices. I've looked around other sites and forums, like Reddit. No one has talked about this so perhaps you are right. It's just not a big a deal to justify action against Apple.

I had the exact same issue as everyone here. The first few nights (2 or 3), I used multiple pixel refresher videos from YouTube (5 hours or so each time), at max brightness. Then I continue to use the computer normally but on a second screen. Keeping the iMac screen at the lowest brightness for over a week.

Also, I pray a whole bunch :)

Understood, just trying to help with this part of the post...

Does this mean that the microphone is on and it is recording? Does anyone know anything about this light? This light appeared after the first of the two major updates.

It seems like more and more Mac users are experiencing this line problems with their computers. Apple should be able to address and find solutions for this issue, as even users with newly purchased units are facing the same problem. This is a product defect issue. They should make sure to test their product before releasing to public.

Sadly, this is the community forum. No one at Apple Support or up will respond. I don't even think they read this stuff here. Anyway, you can bring it to the Apple Store, call Apple Support since this is a hardware issue and not software. Hopefully you have AppleCare and that will cover the cost of the repair.

Hi there,

I'm having the same problem with my iMac. While I'm on a video call, my screen suddenly doesn't look right, like it's covered with a screen. Tried restarting, updating the system, and safe mode to no avail.

I bought it in the UK in September 2021. The specific model is MGPH3B/A. iMac m1 4 ports.

I was originally going to follow the advice of Apple customer service and take it to an Apple store. Thank you everyone for your comments, which saved me a time-consuming and labor-intensive journey. Replacing the screen is really expensive. I'll probably look for any replacement monitors with a similar resolution to the iMac.

Hope to see any updates.

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.