My experience with Apple repairs is a mixed bag. For several iPhone repairs over the years the experience has always been easy and positive. However last year

My experience with Apple repairs is a mixed bag. For several iPhone repairs over the years the experience has always been easy and positive. However last year I bought my first iMac, an i7 27” 5K. Last month a line appeared in the display; a vertical column of pixels were stuck black. The issue is intermittent but I took pictures when it happened. In store they were happy to schedule warranty repair of the display even though the probably wasn’t occurring the moment when we booted. But I got a call from Apple yesterday saying my repair was “completed”, they found the problem, it was the two 16GB sticks of RAM I added. They said because it didn’t match the other two 8GB sticks it would cause display issues. Of course Apple’s own docs state you can mix sizes as long as you do it in pairs and keep the matching pairs on the same bank. How RAM would cause a single column of stuck pixels is beyond me. My only hope is it reproduces again without the RAM present before the 1 year warranty runs out in 3 weeks. Bah!