Over the past year and a half, some owners of the 24-inch iMac with the M1 chip have encountered a problem.

Horizontal lines are appearing on their screens. Complaints about this can be found on Apple’s support site, MacRumors forums, Reddit, iFixit Answers, and several other websites. However, it is unclear how widespread the issue is.

For many affected users, their iMacs are between 18 to 24 months old, and it is during this time that the lines begin to appear. Nevertheless, Apple has provided free repairs to some customers (though not to everyone).

One commonly mentioned symptom is that the top-right corner of the iMac becomes hot to the touch. However, it is unclear what the cause is.