When hardware scheduling you are scheduling the player PC to turn off.
This means that when the player is turned off you can´t reach it from the DISE portal until it is scheduled to turn on again.
So the only way to get the hardware to turn on before it is scheduled to is to physically go to the player and turn it on.
Where to find hardware scheduling
Hardware scheduling can be found by clicking on the hardware tab under a Premium player.
The hardware scheduling feature is only available for Premium players, you can however schedule the screen of Lite players, for more information see: set-up-screen-schedule
The scheduling works the same way as all the other scheduling in the DISE portal, you can read more about scheduling here: scheduling-in-dise-portal