Recently I upgraded my 2015 IMAC to Catalina. Now on first start up in the day, the display brightness automatically resets itself to zero and the system preference brightness setting stops working and I cannot reset screen brightness. I need to do two or three shutdowns. also the restart function does not work. The IMAC shuts down but does not restart. Any diagnosis, solutions.
iMac 21.5″, macOS 10.15
First, there is no reason to ever install or run any 3rd party "cleaning", "optimizing", "speed-up", anti-virus, VPN or security apps on your Mac. This user tip describes what you need to know and do in order to protect your Mac: Effective defenses against malware and other threats - Apple Community.
There are no known viruses, i.e. self propagating, for Macs. There are, however, adware and malware which require the user to install although unwittingly most of the time thru sneaky links, etc.
Anti Virus developers try to group all types as viruses into their ad campaigns of fear. They do a poor job of the detecting and isolating the adware and malware. Since there are no viruses these apps use up a lot of system resources searching for what is non-existent and adversely affect system and app performance.
There is one app, Malwarebytes, which was developed by a long time contributor to these forums and a highly respected member of the computer security community, that is desshoigned solely to seek out adware and known malware and remove it. The free version is more than adequate for most users.
Also, unless you're using a true VPN tunnel, such as between you and your employer's or bank's servers, they are useless from a privacy standpoint: Public VPN's are anything but private.
CleanMyMac is considered akin to malware by most of the experienced contributors to these forums. Uninstall it according to the developer's instructions.
You can check to see if you've removed all of the supporting files by downloading and running the shareware app Find Any File to search for any files with the application's or the developer's name in the file name. For CMM software you'd do the following search(es):
1 - Name contains cleanmymac
2 - Name contains macpaw
Any files that are found can be dragged from the search results window to the Desktop or Trash bin in the Dock for deletion.
FAF can search areas that Spotlight can't like invisible folders, system folders and packages.
First, there is no reason to ever install or run any 3rd party "cleaning", "optimizing", "speed-up", anti-virus, VPN or security apps on your Mac. This user tip describes what you need to know and do in order to protect your Mac: Effective defenses against malware and other threats - Apple Community.
There are no known viruses, i.e. self propagating, for Macs. There are, however, adware and malware which require the user to install although unwittingly most of the time thru sneaky links, etc.
Anti Virus developers try to group all types as viruses into their ad campaigns of fear. They do a poor job of the detecting and isolating the adware and malware. Since there are no viruses these apps use up a lot of system resources searching for what is non-existent and adversely affect system and app performance.
There is one app, Malwarebytes, which was developed by a long time contributor to these forums and a highly respected member of the computer security community, that is desshoigned solely to seek out adware and known malware and remove it. The free version is more than adequate for most users.
Also, unless you're using a true VPN tunnel, such as between you and your employer's or bank's servers, they are useless from a privacy standpoint: Public VPN's are anything but private.
CleanMyMac is considered akin to malware by most of the experienced contributors to these forums. Uninstall it according to the developer's instructions.
You can check to see if you've removed all of the supporting files by downloading and running the shareware app Find Any File to search for any files with the application's or the developer's name in the file name. For CMM software you'd do the following search(es):
1 - Name contains cleanmymac
2 - Name contains macpaw
Any files that are found can be dragged from the search results window to the Desktop or Trash bin in the Dock for deletion.
FAF can search areas that Spotlight can't like invisible folders, system folders and packages.
The best antivirus, cleaning app, and overall maintenance app for Mac OS is Mac OS itself. All you need to do with Mac OS to keep it secure and running well is to keep it up-to-date and do periodic (about 1x per week) restarts. Other than that, leave it alone. Adding third party antivirus, cleaning, security and other types of maintenance apps to Mac OS adds no additional level of security. The only thing these apps do is have the opposite affect users want. They make Mac OS slow, unstable, generate odd behavior (much like you are experiencing) and make Mac OS appear buggy.
Please locate the developers uninstall instructions for CleanMyMac and follow to the letter. Then restart in Safe Mode per the directions in Use safe mode to isolate issues with your Mac and then restart normally.
Please restart in Safe Mode ( Safe Mode Reset ) and then restart normally and re-test the computer.
Yes, I do have CleanMyMac installed on my Mac. Also, today I noticed Mac behaving in strange ways, like when I click Potos icon in the doc with mouse, the systems preference window opens up automatically. I think it is emulating the last run command and rerunning it for all clicks. It could be that the mouse driver has an issue?
Tried starting in Safe Mode. However, the problem has not been resolved. It again dims the display to zero brightness.
By chance do you have any third party antivirus, cleaning or any other third party "maintenance" apps installed?
What @rkaufmann was getting at is that you need to remove 3rd party antivirus. Not needed and frequently will introduce new problems.
IMAC Display brightness problem
