iMac keeps shutting down and experiencing slow performance

sciencemagic wrote:

Thank you for your reply. Sorry, but could you explain how I boot into macOS. When I go to Google and ask about booting into macOS there are several options, Startup Manager, macOS Recovery and Starting from a Bootable Installer or Disk Image. Can you please explain? Once I get that I believe I can execute EtreCheck.

Ideally when you power on the Mac it should automatically boot into macOS (normal/regular boot).

If a normal boot fails, then try booting into Safe Mode instead.

If neither of these two boot modes work, then you have to resort to the instructions in the following Apple article (won't be able to run the third party app EtreCheck though):

If your Mac doesn't start up all the way - Apple Support

When the mac shut down and then restarted, on its own, I saw the error report that was created and I sent that report to Apple. Not sure what happens when that report gets to Apple? Does Apple automatically fix the issue?

Being the shut down occurred 3 times within a half hour and each time I sent the error report, it seems Apple wasn't able to correct the problem?

Apple will not contact you. I imagine Apple takes note of the details to see if they notice any failure patterns with other reports they receive which may indicate an issue with macOS they could tweak or even fix, or notice a hardware issue exists.

When I started my mac this morning, it was started from being asleep, (which is how I shut down my mac) and my computer acted peculiar at start up like it hasn't before. But, then when I purposely shut down the mac and hit restart, my mac seems to be working fine now?

So, is it worth me performing what you suggest, HWTech?

Yes, please run the third party app EtreCheck and post the complete report. It will include log summaries which may help us to identify a problem and it will also include hardware & software information for us to evaluate. Many crashes are due to issues with third party software people have installed, but sometimes the crashes can be due to a hardware issue. This report is the easiest method for us to assess your system.

Certainly appreciate your help, but I don't want to screw something up on my mac being I'm NOT well versed in solving computer problems. But, appreciate the help, HWTech.

The EtreCheck app does not install anything on your computer so it won't negatively impact your system. Once we are finished troubleshooting your system, then you can delete the app easily.

If you are able to boot into macOS, then run the third party app EtreCheck and post the complete report here so we can examine it for clues.

How to use the Add Text Feature When Posting an EtreCheck Report - Apple Community