iMac M1: All-in-one PC reportedly has a hardware defect - Apple refuses free repairs, high display brightness is a risk

At present, it is not yet really clear just how widespread the hardware problem really is. Forum posts can give a somewhat distorted impression and easily lead to an overestimation of certain issues, as only affected users - possibly several times and across several platforms - report the problem, while hundreds of thousands of iMacs may be working perfectly well.

In this case, the problem described is interesting insofar that is clearly a hardware defect. The error itself: persistent horizontal lines appear on the display of the iMac M1, which severely restrict the usability and visual appeal of the display. The issue can be traced back to the display relatively quickly, as affected users can still use an external screen without issue. This rules out a defect with the iGPU.

In detailed discussions on various platforms, affected users describe their experience. Apple's handling of the problem appears to differ from case to case, but is generally proving unacceptable among customers. Apple is currently refusing to repair out-of-warranty devices as a rule, as it has not yet admitted to a serial defect. In the Apple forum, one user gives a relatively detailed description of the error: thermal damage to a cable, which limits signal transmission. The higher the selected display brightness, the more likely the cable will incur thermal damage. The cable cannot simply be replaced, which makes potential repairs more costly.