The power button on LabQuest 2 functions differently depending on the state of unit when you press it.
Note: Powering the unit down will not fix an issue with screen calibration. See TIL 2766: LabQuest 2 screen is unresponsive or acts like I am tapping on the wrong spot.
The screen is off
If the screen is off, pressing the power button briefly will turn it back on. The screen can be turned off for any of the following reasons:
1. The screen is off to conserve power. This is an adjustable setting found by tapping Home > Preferences > Light & Power.
2. The unit has been turned off (i.e., to suspend the unit).
3. The unit has been shut down.
The screen is on
When the LabQuest screen is on, there are three different power down options:
1. A brief press will turn the unit off (i.e., suspend the unit). Powering back on from suspend is faster than powering on after a shut down; however, LabQuest will continue to slowly drain the battery while suspended.
Note: You don't get feedback on the button press until you let go of the button.
2. If you hold the power down for 5 seconds, a message will appear and advise that LabQuest is going to shut down. This method is recommended when you will not be using LabQuest for extended periods of time.
3. If you continue to hold the button down for a total of 8 seconds, the unit will power off uncleanly. This is the same as pulling the battery out of the unit while it is running or pressing the reset button on the back of an original LabQuest.
Note: This method should only be applied if you have no other options as it can potentially lead to file system corruption.
TIL 2018: What is the best way to store LabQuest units over summer vacation?