I am on my second Optiplex 7470 AIO at work, due to an odd shutdown issue. This is a work PC, so we have a number of them, but I seem to have been the only one running into this issue, as far as I know.

The issue seems simple, but I've had no luck narrowing it down. I have an issue where the system just shuts off. Power light is dead and it won't even respond to the power button. I need to unplug the AC power cord from the rear of the unit before it will allow me to restart the system. In event manager there is no error that I can see related to the shutdown except for a "The previous system shutdown at time on date was unexpected." one. This was the exact same issue I had with the last, identical system of this configuration I had, so I found it odd and figured I'd check in here, before I have the actual time to file a support claim.

FYI, this is the i9 variant of this model. While I do have access to the i7 model as well, the current ones are all deployed, so I would have to wait until we get another batch in the office, if I were to try to downgrade. Besides this issue the only one I really have with the system is the maxing out of the fans sometimes when Chrome starts to eat up resources. 
Would be glad to provide additional info, just ask.
Thanks.