iMac potential graphics issue

I have noticed my iMac screen locks on the attached distorted screen. It seems to happen when the mac is left unused, before the screensaver should kick in. This is an intermittent fault. The screen will stay on like this indefinitely (so the screensaver and sleep mode is not kicking in) but the screen returns to normal if I press escape.


Has anyone experienced similar or recognise what the issue may be?

iMac 27", macOS 10.14

Posted on Feb 16, 2020 2:21 AM

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Posted on Feb 16, 2020 7:04 AM

Could be the GPU getting ready to fail. However first reset the NVRAM and restart in Safe Mode if both of these fail to resolve the issue, please take the computer to your local Apple Authorized Service Provider to be professionaly diagnosed.


How to reset NVRAM on your Mac


How to reset NVRAM on your Mac


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Question marked as ⚠️ Top-ranking reply

Feb 16, 2020 7:04 AM in response to LathamPJ

Could be the GPU getting ready to fail. However first reset the NVRAM and restart in Safe Mode if both of these fail to resolve the issue, please take the computer to your local Apple Authorized Service Provider to be professionaly diagnosed.


How to reset NVRAM on your Mac


How to reset NVRAM on your Mac


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Feb 16, 2020 10:35 AM in response to LathamPJ

Have you blown the dust out of the intakes lately?

What temperatures does this App report?

This App can be used to speed up the fans, all my iMacs would be dead without it.

Never ever ever drop fan speeds below the speed that the Mac itself is calling for.



MacFansControl…

https://www.crystalidea.com/macs-fan-control

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iMac potential graphics issue

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