in my iMac (Retina 4K, 21.5-inch, 2017) there is blurred/lightup border which appears even in the apple logo screen at boot time. it's increased lot in last few weeks. it's same in any OS version. i have more than two iMac. this problem in all iMac. i can't find where is exact problem. any solutions?
iMac 21.5″ 4K, macOS 10.15
Thank you for reaching out to us here in Apple Support Communities with the screenshot samaj1. We do see the issue at hand and we'll be happy to help advise.
Have you tried restarting your Mac to see if that helps? If so, you can test this issue in and out of safe mode. Safe mode will clear your system cache and attempt to repair any directory related issues. Start up your Mac in safe mode
You can also reset the NVRAM on your iMac to help isolate. This article will help: Reset NVRAM or PRAM on your Mac
If the issue continues after resetting your NVRAM you can isolate this further by booting into macOS Recovery, and see if the issue happens there. This can help confirm a hardware related complication.
Take a look: About macOS Recovery on Intel-based Mac computers
If this happens in macOS Recovery, you can reach out to Apple Support directly to help explore inspection options.
Warm regards.
Hey there samaj1,
We appreciate you giving those steps a try and keeping us updated. Since the issue seems to continue, we would recommend that you reach out to Apple Support directly. That way they can hep you explore inspection options. The link below will help.
Cheers!
I tried all the things mentioned above, but still have problems.
iMac (Retina 4K, 21.5-inch, 2017) there is blurred/lightup border in iMac
