Mac loses power during the day?

[tbealmear]

I sleep my mac when I go to work in the morning. Sometimes however when I get home, it is at the login screen like it lost power or something in the middle of the day. Is there a easy way to look at any system logs to see what exactly might be happening and when? It has happened 2 or 3 times within the past two weeks. I guess I will leave it on and see what happens then.

 

[old-wiz]

System log will show what's happening to some degree. Typically you will see a gap in the log and looking around that area will show something. When the system shuts down, you see log entries indicating that a shutdown is in progress, for example. It could also be a real power failure or distruption in the power. There's a setting in System Preferences to not restart on a power failure - I keep that set since often a power failure is followed by a surge which can damage equipment.