You can see those " Lines " Below Mac Rumours. Yesterday I do contact to an Apple advisor. She told me , I take screen shot of it from my M3 iMac those lines will not shown. She just keep tell me bring to Apple store check. I don't want to waste my time. All fellow M1 to M3 iMac users already went to Apple store get it check end of the day Need to Pay get it fix and they don't pay to get fix. Some still continue using it despite got lines whereas some connect to Another monitor without looking at iMac screen.
This photo is taken from my iPhone 15., I do check around in here Apple community even almost entire internet online. A lot M1 to M3 iMac users encounter these " Lines " suddenly appear upon using it after one year and so and obviously Warranty is over..
I have restart Many times. Even turn off the main power , wait for few mins and turn on the M3 iMac the lines still there. When the iMac start boot up, I already noticed those lines appear. It will be white under black screen.
My usage is NEVER GPU aggressive, like playing intensive games. I not a gamer. I never play any games on my M3 iMac. I only do Simple task come work on this iMac. Come entertainment only see Youtube and Live stream.