Previous shutdown cause: 0

[dimme]

I been having a intermit problem where my 2019 iMac 5K w/3.6 i9 and Vega 48 will just turn off. It usually happens when I am running X plane, but has also happened running light room and photoshop. I am not sure where to look in the console app to figure out what is going on. I have run Previous shutdown cause in the terminal and always get Previous shutdown cause: 0. Which indicates power disconnect. I have tried to duplicate the shutdown running handbreak and CPU stress test at the same time but I have not had any luck. I running the latest Catalina with all the updates. I also reset the SMC, checked the power cord and the computer is plugged into a proper sized UPS.
Any help in trouble shooting would be appreciated.
Thanks

 

[DeltaMac]

Do you only get those shutoffs when the system is under load?
Or have you seen any shutdowns when the system is mostly sitting at idle?

Have you checked the "simple stuff"?
Loose power cord?
Intermittent connections on your surge protector/power strip?

That's a pretty simple cause, so if there's no simple "loose power cord", or failing surge protector, and this is something that has only started recently, I would suspect a failing power supply, which probably can't handle the load, and rudely shuts off when there's more power needed.

 

[dimme]

Thanks for the suggestions, I did check the simple stuff like you said. And yes it only happens under load. I sure would like to duplicate the problem so if it is a failing power supply I can get it fixed with applecare. That why I was hoping it would be in some log file or something.

 

[DeltaMac]

You say you have AppleCare.
I think you should use it... Call AppleCare for support with that.

 

[dimme]

You say you have AppleCare.
I think you should use it... Call AppleCare for support with that.

I plan too but I was hoping to gather more information before I call. I found with AppleCare the more info you can give them the better they can solve the problem. Thanks why I am hoping to find some information for a system log.

 

[DeltaMac]

You could boot to your built-in diagnostics, and see if you get any trouble codes...