You can try these codes on Samsung,HTC and other cell phones which have android OS.
OK let's start:
- *#*#4636#*#* :You can get access to phone,battary and usage statistics....
 - *#*#7780#*#* :Your phone returns to its fabric settings...
 - *2767*3855#:This code makes a full erase and installation ...
 - *#*#34971539#*#* :shows about the camera info...
 - *#*#7594#*#* :changes behaviour of power button....
 - *#*#273.283*255*663.282*#*#* :backs up quickly all media data...
 - *#*#526#*#* :makes wireless LAN tests...
 - *#*#232.338#*#* :monitorizes the Wifi ,MAC Address
 - *#*#1472365#*#* :quick GPS test
 - *#*#0*#*#* :LCD screen test
 - *#*#0289#*#* :sound test
 - *#*#0842#*#* :vibration and backlight test
 - *#*#2663#*#* :monitorizes touch screen version
 - *#*#2664#*#* :touch screen test
 - *#*#0588#*#* :Proximity sensor test
 - *#*#3264#*#* :RAM version
 - *#*#232331#*#* :Bluetooth test
 - *#*#7262626#*#* :range test
 - *#*#232337#*#* :monitorizes the adress of bluetooth device...
 - *#*#8255#*#* :for watching "Google Talk" service...
 - *#06#:shows IMEI number
 
