Suddenly, the bottom half of the screen filled with horizontal black lines. The horizontal lines flicker continuously. It occurred while I kept my Mac stationary without moving it at all. It's clearly a defect with the display because it happens without a cause.
My iMac only 2 year old. I can't believe that it is a coincidence that it is happening to so many people almost exactly 2 years after purchase.
iMac (M1, 2021)
Hi, me too. it just happened suddenly.
Probably the most affordable method by far is to connect an external monitor if you can accept a relatively lower resolution. I replaced my iMac by buying a studio display to connect my MacBook Pro and just put my iMac in the box. I am not going to repair my iMac because I don't know if similar problems will occur again, and the new screen only has 3 months guarantee.
By the way, i donot know why my previous comment has been deleted...
Best,
Schedule Apple in-store repair for a free diagnosis and repair estimate.
Persistent horizontal lines appear on iMac M1 screen
