Screen Lock/Unlock; Activating/Deactivating Display; Volume Controls - Lenovo TAB A7-40 User Manual

Volume Controls

Press the Volume Up or Volume Down button to adjust the volume.
1-3 Activating/Deactivating the Display
Activating the Display
With the display deactivated, press the On/Off button on the tablet to
activate the display. The tablet's display will then illuminate, indicating that it
has been activated.
Deactivating the Display
If you do not need to use your tablet temporarily, you can press the On/Off
button to deactivate the display. Your tablet will then enter standby mode to
save power.

1-4 Screen Lock/Unlock

Screen Lock
Auto-Lock
You can set screen timeout by tapping
> Sleep. If there is no operation within the preset standby time, the display
will automatically deactivate, and your tablet will be locked automatically.
Manual Lock
If you do not need to use your tablet temporarily, you can press the On/Off
button for about 1 second to deactivate the display. Your tablet will then be
locked, and will enter standby mode.
Screen Unlock
When in standby mode, press the On/Off button on your tablet to activate
the display. Then, tap and hold the lock icon, and drag the slider over the
unlock icon, as shown in the illustration below.
Settings > DEVICE > Display