By default, Philips TV is set with Auto Standby set to On..
This means that if there's no video signal for 10 minutes, the TV will turns off (to standby)
It also means that if there is no user interaction within the specified time, the TV will turn off (to standby)
And by default the Auto Standby period for no user interaction is 4 hours.
To disable Auto Standby or to change the Auto Standby Time:
- Go to Professional Menu (press 3,1,9,7,5,3,mute)
- Navigate to Advanced->Power->Auto Standby, set this to 0 to disable