You can create an event log filter to show sleep and wake events: Sleep history: [Event sources = Kernel-Power, Power-Troubleshooting] and [Event IDS = 1,42]
If you want to see more power events, just remove the “1,42”
Maybe it looks like it's going to sleep, but the event logs say it's not? Maybe it's going into “connected standby”, which you'll see in the event logs as:
Log Name: System Source: Microsoft-Windows-Kernel-Power Event ID: 506 Task Category: (157) Level: Information Keywords: (4) User: SYSTEM Computer: ADMIN-NOTE01.atcna.local Description: The system is entering connected standby Reason: Idle Timeout.
Windows 8 has redefined what we computer users think of as "standby." Now, if the screen turns off it is actually a form of standby. I believe it is called “connected standby.” Therefore, if the option to require password on wakeup is set it also locks when the screen simply turns off.
However, for domain connected computers you can set the following group policy to stop this behavior. It is the policy that controls the above listed registry key: [HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\System]
The policy is under [Computer\Administrative Templates\System\Logon] - Allow users to select when a password is required when resuming from connected standby - Enabled.
My current setting for Surface Pro's, we'll see if this works: