Hello, I have an iMac that keeps shutting itself down and need help. thanks. Jim

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Hello Jim I'm happy to assist you here.

Does it actually restart or does it just shut off as if you've  pulled the power cord?

Please let me know by typing a response at the top and clicking on send response

Hi Jim

Just to confirm. It only does shut off once you hit the sign in screen and not random shut off? 

OK. Try the following steps for us to isolate the problem.  

1. Shut down the computer.
2. Unplug the computer's power cord.
3. Wait fifteen seconds.
4. Attach the computer's power cord.
5. Wait five seconds, then press the power button to turn on the computer.
6. Press and hold the Command-Option-P-R keys before the gray screen appears.
7. Hold the keys down until the computer restarts.
8. Release the keys.

Alright. Are you now in the sign in sreen? 

Can you try to sign in  

OK. I'll be standing by

You can close that message. 

 Restart your Mac, then immediately press and hold the Shift key. Release the Shift key when you see the login window. We will try the safe mode,  

That's nomal when trying to go on safe mode 

Let go of the shift button 

sign in  again 

do you mind if i call? 

do not close this screen. I'll be giving you call.  

Details: Will continue troubleshooting on tuesday | issue persistent