Dell Mini 3v - Manual (Page 13)

1. Screen
2. Suggestion list
Sleep Mode
After a period of inactivity, your phone enters the sleep mode (no image appears on the display). While in sleep mode, the smartphone saves battery power.
Waking Up the Phone
1 Press the Power button to wake up the phone.
2 Align the moving blue circle on the lower left corner of the screen.
Phone Lock
When not on a call, you can lock the control buttons and the screen for security and to avoid accidental touch activation.
Locking the Phone
1 Tap Settings on the Home screen, and then tap Security > Phone Lock Settings to open Phone Lock Settings screen.
2 Enable the Phone lock function by selecting the Phone lock check box.
3 Enter a 4-8 digit phone lock password.
Tap the Numbers and Symbols icon to change the input to numbers and symbols.
Tap the Back icon to exit the input panel.