I have an iMac (21.5-inch, Late 2012) desktop and I received a message the other day that Apple was going to send update version mac OS Catalina 10.15.7. after that my computer will not come on past the Apple icon - no downloading bar. Any help?
[Re-Titled by Moderator]
Here are the Apple suggestions:
If your Mac doesn't start up all the way - Apple Support
Run hardware test. (This Mac is too old for Apple Diagnostics.) If you don’t still have the DVD for Hardware Test, here are links to downloads located at Apple that can be used to create a DVD:
https://github.com/upekkha/AppleHardwareTest
Try booting into Safe Mode:
Start up your Mac in safe mode - Apple Support
If this is the iMac 8GB HDD config, it’s going to be slow even when it’s working, and its performance can potentially be assisted with an external SSD:
Why is my hard disk drive iMac so slow? - Apple Community
Here are the Apple suggestions:
If your Mac doesn't start up all the way - Apple Support
Run hardware test. (This Mac is too old for Apple Diagnostics.) If you don’t still have the DVD for Hardware Test, here are links to downloads located at Apple that can be used to create a DVD:
https://github.com/upekkha/AppleHardwareTest
Try booting into Safe Mode:
Start up your Mac in safe mode - Apple Support
If this is the iMac 8GB HDD config, it’s going to be slow even when it’s working, and its performance can potentially be assisted with an external SSD:
Why is my hard disk drive iMac so slow? - Apple Community
My late 2012 iMac is stuck on Apple logo since updating to macOS Catalina
