iMac M1 2021 screen discolouration

[Lulitta6]

I was using my iMac, and then took about an hour break from work, and when I came back to it the screen was dark and the colours were all distorted. Almost like the colours were inverted, but not quite. I attached a photo. I tried restarting it, and shut it down for a bit and came back to it, but it looked the same. Except one time I restarted it it the screen was lighter and washed out (photo attached).

I contacted apple support and they had me do a few things such as do a test user, reinstall the disk, etc., but the only thing that somewhat worked was starting it up in safe mode. When I did this (and then restarted it again), everything looked normal again except very faded. At least then I was able to use it to finish work for the day, and after some time, it all seemed to brighten up a bit and almost be back to normal.

When I shut it down again and started it back up the next day it was back to distorted colours.
Also, if I took a screenshot on the iMac and sent it to another device, it looked completely normal. Not sure what that means..

Anyone know what this could be?? We are in a pretty intense heatwave where I am (41 degrees C every day for a week so far) so not sure if it could be heat related?

I'm 2 hours away from the closest Apple Store so trying to see if this something I could fix myself before taking it in. Thanks!

 

[leifp]

A screenshot isn’t taking a photo of your screen, it’s taking a capture of the output from the computer itself, thus it will have no correlation with a misbehaving screen.

I cannot speak to your specific problem as my own happened on an external display and my solution will not help you at all - connecting a new Mac fixed it… which leads me to believe that the issue is the GPU, which on an M series Mac will mean a motherboard replacement.

Sorry I could not give you good news. While it might “fix itself” that is unlikely. You may need to go for a drive…

aside: I notice in the second image that you seem to have screen retention of icons. I’ve never seen that except on OLEDs (which your display is not). Is that correct, can you see those files even on the Lock Screen?

 

[FreakinEurekan]

Agree, if a test user looks the same - probably a hardware issue. Safe Mode disables GPU acceleration but as @leifp said the GPU is integrated so that knowledge doesn’t help the situation much.

 

[Lulitta6]

A screenshot isn’t taking a photo of your screen, it’s taking a capture of the output from the computer itself, thus it will have no correlation with a misbehaving screen.

I cannot speak to your specific problem as my own happened on an external display and my solution will not help you at all - connecting a new Mac fixed it… which leads me to believe that the issue is the GPU, which on an M series Mac will mean a motherboard replacement.

Sorry I could not give you good news. While it might “fix itself” that is unlikely. You may need to go for a drive…

aside: I notice in the second image that you seem to have screen retention of icons. I’ve never seen that except on OLEDs (which your display is not). Is that correct, can you see those files even on the Lock Screen?

Yes the Lock Screen is slightly visible when on the Home Screen and vice versa.

 

[bad_robot]

I was using my iMac, and then took about an hour break from work, and when I came back to it the screen was dark and the colours were all distorted. Almost like the colours were inverted, but not quite. I attached a photo. I tried restarting it, and shut it down for a bit and came back to it, but it looked the same. Except one time I restarted it it the screen was lighter and washed out (photo attached).

I contacted apple support and they had me do a few things such as do a test user, reinstall the disk, etc., but the only thing that somewhat worked was starting it up in safe mode. When I did this (and then restarted it again), everything looked normal again except very faded. At least then I was able to use it to finish work for the day, and after some time, it all seemed to brighten up a bit and almost be back to normal.

When I shut it down again and started it back up the next day it was back to distorted colours.
Also, if I took a screenshot on the iMac and sent it to another device, it looked completely normal. Not sure what that means..

Anyone know what this could be?? We are in a pretty intense heatwave where I am (41 degrees C every day for a week so far) so not sure if it could be heat related?

I'm 2 hours away from the closest Apple Store so trying to see if this something I could fix myself before taking it in. Thanks!

The fact that screenshots look normal on another device suggests it's a display or graphics problem. The heatwave could be contributing to it, so make sure your iMac is well-ventilated. Try checking the display settings, connecting an external display, or running a diagnostic test to see if you can pinpoint the issue before taking it to the Apple Store.

 

[DeltaMac]

Do a full power-off: Shut down, then unplug from power (disconnect the power cord, also disconnect any external device that has its own power, such as a wall-wart.)
The idea here is to remove power completely, then leave it off for and hour or two, over night is even better. Plug power back in after that time.
This is just something to try. If it helps, then you still likely have a problem, as the improvement in screen may only be temporary.