Brand new iMac shuts down unexpectedly, doesn't want to power on, and wait there's more!

Purchased in April an iMac, 24 inch M1.

About a month later it started randomly shutting down. 

Was difficult to restart.


July 2 opened case with Apple support.


Told me to reinstall Mac OS.

Tried several times, but would not reinstall.

Finally it shut down and reopened in safe mode.(Without my help)

Then I was able to reinstall the system.


Downloaded Clean My Mac to check for malware.

Changed power plug strip.

Checked everything I could.


Started shutting down by itself again. Very difficult to restart.

Have to press the on button 10 to 30 times to get it to start up.

Also sometimes when it starts up it has to be restarted again to get it to function as the status strip is missing on restart.

Also sometimes when you actually shut it down it starts right back up by itself.


Opened case with Apple and was told to take to Apple Store.


Took it to the Apple Store and they replaced the Logic Board and also the Ambient Light Sensor and Microphone cable.


Had it back home for about 3 weeks, it shut down twice since then but was not a problem until now.


Sept. 14 it was shut down when I got up, would not start up for about 10 minutes, tried about 80 times. Finally came back on and the status bar was missing. I restarted it, and then it shut itself down again twice, finally the 4th time it restarted with the “Your Mac shut down because of an issue” prompt. Sometimes when it restarts itself it will flash bright pink.


Sept 15, shut itself down during the night, came back after pushing on about 30 times, worked immediately.


Also Sept 15 shut down during the day, restarted 4 times until status bar came up when it was an instant restart by itself.


Sept 15 I shut it down for the night and it restarted instead and said it had shut down because of a problem even though I had shut it down.


Sept 16, wasn’t on in the morning, took about 10 minutes and three or four restarts to come back on with status bar. Same thing happened in the afternoon. When I try to restart it shuts down instead.


This rarely happens when I am using the computer, only when it is not in use.


[Edited by Moderator]

Posted on Sep 16, 2023 12:19 PM

Reply
17 replies

Sep 16, 2023 2:20 PM in response to touchtone

You've compounded the problem by installing what most long time users here consider akin to malware: CleanMyMac.


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 documents describe what you need to know and do in order to protect your Mac: Effective defenses against malware and other threats - Apple Community and Recognize and avoid phishing messages, phony support calls, and other scams - Apple Support.  


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 designed solely to seek out adware and known malware and remove it.  The free version is more than adequate for most users.  


Uninstall CMM according to the developer's instarucionts. 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 CMM software you'd do the following search(es): 


1 - Name contains clenmymac

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.  


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.


Sep 16, 2023 4:14 PM in response to touchtone

If you've already reinstalled the OS, then I'd suspect a software or hardware issue. Since it happens intermittently, I'd tend to suspect software.


I'd say there's a pretty good chance the issue reveals itself if you can download/install/run Etrecheck Here. This is a pretty amazing piece of software that digs deep into issues your Mac may have. A couple of notes regarding it:

    • Make sure you allow full disk access when you run it.
    • After running it and the report's been generated, copy it and paste it in your reply here, and we'll be glad to take a look at it. To paste the report, use the Additional Text icon (third from the right at the bottom of the reply window).


Of course, if nothing out of the ordinary appears, you might need to take it to the Apple Store and let them run diagnostics on it, as it's possibly a hardware issue.

Sep 16, 2023 4:32 PM in response to touchtone

CleanMyMac may not have been the initial problem, but it will give you problems when installed making troubleshooting your original issue impossible. Start with a clean install without installing CleanMyMac and run EtreCheck as already suggested.

Using EtreCheck


My first thought would be a RAM issue, but with Apple replacing motherboard it would eliminate most of the hardware issues causing the problem. I suppose they could have just transferred the RAM from the previous motherboard into the new one, but bad RAM is notorious for unexpected shutdowns and would think they would have replaced it as well if they went through the trouble of replacing the motherboard. In addition, you can run the Hardware Diagnostics test to see if anything shows up.

Use Apple Diagnostics to test your Mac - Apple Support

Sep 17, 2023 11:37 AM in response to touchtone

Alas, I have to agree with Old Toad's sage advice. The Etrecheck report didn't show anything that jumped out at me (except for the already mentioned panic attacks).


I'd let the Apple Store have another look, as it doesn't appear there's a software issue. I'd go a step further and have the Apple Store do a complete erase on it and let you start over with a fresh, clean install of MacOS. After that's complete, see if the issues are gone.



Sep 17, 2023 12:02 PM in response to Old Toad

I know, it's just an hour away in bad traffic and I have been there three times in the past 2 months. I am so upset because it is brand new! I usually just pull everything off my old computers and load it on the new one, but this one I wanted to keep clean so I didn't do that and had to set everything up from scratch. Guess that was no help.


I appreciate the time everyone has taken. Thanks for your help.


Brand new iMac shuts down unexpectedly, doesn't want to power on, and wait there's more!

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