Secret Codes For all Mobiles:

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Secret Hidden Codes for All mobiles to Test Functionalities
-Display information about Phone
-Battery and Usage statistics
-Packet Loopback test
-LCD display test
-Audio test
-Vibration and Backlight test
-Displays touch-screen version
-Touch-Screen test
-Proximity sensor test
-Ram version
-Bluetooth test
-Field test
-Displays bluetooth device address
-For Google Talk service monitoring
-PDA, Phone, Hardware, RF Call Date firmware info