Power on the ATC.

Navigate to the main System Screen (PP/AWM/HP).

Launch HP Street Navigation.

To set the Power Management:

Tap on Settings.

Tap on System.

Set "Turn of if idle after:" to Never.

Tap on Home icon.

To Set Backlight:

Tap on Navigation.

Tap on Settings.

Tap on Visual.

Tap on Backlight Settings.

Set sliders for backlight at day and night to your prefernce.

Also set Power Manager to "Backlight Always On"

Tap on the Home icon.

Tap on the X icon to return to the Main Navigation page.