iMac won't connect to internet via ethernet or Wi-Fi after power outage

The second EtreCheck report clearly shows the Symantec is still installed. Please locate the developers instructions to uninstall, then please follow to the letter. Next download FindAnyFile and have it search for anything with the name:

• Symantec
• Norton

in it and move those to the Trash, then empty the Trash. Next, restart again in Safe Mode, then restart normally and re-test.

Do not reinstall Mac OS, it is not MS Windows! Please run and post an EtreCheck report of your system.

Also, do you have ANY of the following types of third party apps installed?

• Antivirus
• Cleaning
• Security
• VPN
• Maintenance

You still have Norton's Symantec installed. Uninstall and check for remnants with Find Any File.

Restart and update the modem, & router, then restart the iMac in Safe Mode, then restart normally and test.

Here is the problem, you have Symantec, and CleanMyMac are installed. At the VERY best these are considered worthless as they NOTHING that Mac OS does not already do. What they do is modify Mac OS to make it slow, unstable and create unwanted actions much like what you are experiencing! Mac OS only needs to be kept up-to-date and to have the computer restarted about 1x per week in order to remain stable, fast, and trouble free.

Please locate the developers uninstall instructions for each and follow them. After they are uninstalled please restart the computer in Safe Mode and then restart and retest. If the problem continues , then please provide a fresh EtreCheck report.

Your problems are caused by those apps. You can search in these forums and you will find hundreds of users with Symantec and CMM that have had nothing but major problems. As mentioned, please uninstall per the developers instructions then double check they are uninstalled (fresh EtreCheck report) and then restart in Safe Mode then finally restart normally and test.

Once the apps are fully uninstalled if the computer works okay then you know Mac OS is okay. If you continue to have issues that means the apps have damaged Mac OS that it needs to be re-installed to fill in missing or damaged aspects of it caused by the Symantec and/or CMM apps.

I'm not "claiming" anything, I am advising you that these apps are considered malware by experienced users, that they cause issues similar to what you are experiencing, and they are they do absolutely nothing that Mac OS does not already do. I understand if you do not want to follow the advice provided, however if you don't you will be rewarded with an unstable, slow and buggy Mac.

Following Old Toad's advice would also be very wise after you have uninstalled the apps.

Once you uninstall Symantec and CleanMyMac according to the developers' 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 the software mentioned you'd do the following search(es): 

1 - Name contains cleanmymac

2 - Name contains macpaw

3 - Name contains symantec

4 - Name contains norton

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.  

If you get warnings that the file can't be deleted because it is in use or used by another app boot into Safe Mode according to How to use Safe Mode on your Mac and delete from there.

Note:  if you have a wireless keyboard with rechargeable batteries connect it with its charging cable before booting into Safe Mode.  This makes it act as a wired keyboard as will assure a successful boot into Safe Mode.

Then it is time to do an erase and install to start all over, this is an example of the worse case scenario that installing these types of apps have on Mac OS!

Very sorry to hear this and we know it’s a painful lesson but I’m sure one that will not soon be forgotten!

So, before the power outage everything worked fine - even with the s/w you claim is causing the problem. Then what? The power outage activated something in Cleanmymac that broke the users connection?

[Edited by Moderator]

And you clearly do not read what we read daily from users that have troubles due to these apps. Post something useful sport!