Horizontal lines at the bottom of iMac(M1,2021) screen

It is a common hardware fault as can be seen from various posts in the Apple Community pages.

I checked with the Apple service provider. The cost of repair is Indian Rupees 50,683 =USD 600 at the current exchange rate (which is around USD 2,100 in Purchasing Power Parity).

My thoughts on this are unprintable.

Thanks for all your help.

FWIW, it's a hardware problem and needs looked at by Apple.

Even I too have same issue I bought iMac 24 inch M1 in 2021, I normally use 2 to 3 days in a week, all of sudden screen started flicking. Apple service Center suggested for screen replacement which cost approximately $900 SGD. I am not sure how apply is selling products now a days with loss of trust on their products.

There is no software solution, you will have to contact Apple to get it fixed.

My guess is your graphics card has tanked, probably through overheating. *Or* your video cable has gone bung. You can’t do anything about the graphics card in an integrated logic board, so it would cost a packet to replace the logic board. If you hook it up to an external monitor do you have the same issue?

Screen replaced free of cost in apple care scheme. Thanks

After reading all the threads related to this issue, I've contacted Apple chat support and tried to negotiate a free repair for this widespread issue.

Apple chat support said that they don't have the authority to do this and ask me to contact phone support. Phone support said the same thing and asked me to take the iMac and go to Apple store. And Apple Store support said they can't do anything unless the issue appears in this Apple Service Programs list, and he suggested me to leave a message in Apple Feedback.

Everyone, please leave a feedback to make Apple fix the issue.

You won’t find official updates here for this or any other issue. Your only option is to schedule an in-store repair appointment with Apple/Apple-authorized service provider. If their resolution is unacceptable, you can vent your frustration here Feedback - iMac - Apple. Good luck!

If the repair is out of your budget ranger an less costly workaround is to get a 3rd party monitor, put it infant of the iMac and set the iMac's monitor brightness to off and use the 3rd party monitor. 4K monitors can be had for $200 and up for 27" and $300 and for 32": brand LG.

Try safe booting the Mac and see if still occurs

Just for the record, we are just users, and other than offering some hail mary advice can only commiserate with you. If you want Apple to see this send feedback:

Product Feedback - Apple

Exactly the same issue with 24" iMac M1 after 2 years 11 months - only option was replacement of screen at my expense - over £630 - not happy!

Also...

Persistent horizontal lines appear on iMa… - Apple Community

Same solution:

Have it fixed, and send feedback.

Product Feedback - Apple

LuciferYY wrote:

I don't buy Apple Care as I usually buy new devices after 2-3 years. It's a common problem so Apple should look into this and should have a service plan for it.

It's unfortunate and I agree a screen should last much longer than 3 years. I am using an iMac here, 2015 model. Recently recycled an iMac 2008 that failed because of its power supply, not the screen. All computer makers purchase in bulk parts for their products from third parties, there is an acceptance of a certain percentage of failures or defects, maybe a percent or so. At work, we have quite a number of iMacs and Mac laptops, I noticed that my employer now has Applecare+ on all of them. And we are required to replace all computers every three years at work. I have never seen one of those iMacs fail, so the percentage might be low.

All my personal Macs are laptops or iMacs, which have a lot of chips and hardware fit into very tight spaces. This makes them prone to thermal issues or other internal connector problems, hence I always get the Applecare+ and consider it simply part of the cost. We have actually never made a claim for a Mac (we have had many, so I guess we have actually lost money on buying the Applecare+ there), but my daughter has had two claims on iPhones which resulted in new phones.