Distorted Screen on old iMac and new iMac

[komatsu]

A user had a 2016(?) iMac running High Sierra where the screen went all distorted.

Classic symptoms of a GPU failure - black and white in some place, bright green and blue in others.

However, it did allow the user to perform a TM backup.

User buys new iMac system. TM backup migrated - guess what? exact same problem of distorted screen.

Anybody come across this before?

 

[Cruz3LT]

A user had a 2016(?) iMac running High Sierra where the screen went all distorted.

Classic symptoms of a GPU failure - black and white in some place, bright green and blue in others.

However, it did allow the user to perform a TM backup.

User buys new iMac system. TM backup migrated - guess what? exact same problem of distorted screen.

Anybody come across this before?

I would say it wasn't a GPU failure then. Sounds more like a software hiccup that he brought over to the new machine. Did he run a diagnostic on the 2016? If they did, what were the results. My suggestion, wipe the hard drive and install a fresh copy of OS and then transfer files over individually to find the culprit.

 

[komatsu]

thanks for your answer Cruz. Diagnostics revealing nothing.

Old OS wiped. New OS installed. Problem gone.

Truly bizarre. GPU failure was mimicked precisely except it was not the GPU!