CODE 1: *#06# (REVEALS IMEI NUMBER)
When you type *#06# on any mobile phone or tablet that uses SIM cards, the IMEI number of the device is displayed. The IMEI is a unique number that carriers and manufacturers use to identify a device but it can also be used to generate unlock codes to remove the SIM lock.
CODE 2: #31# (DISABLES OUTGOING CALLER ID)
The code #31# hides your phone number when you call someone but it only works on the call you are currently making. Some Galaxy phones require that you combine the code with the phone number that you want to dial (for example #31#phonenumber and then tab the Call button). Some other Galaxy models require that you type the code, tap the Call button, and then dial the number. Try calling your home phone number to see which way it works on your particular model.
CODE 3: *#21# (CHECKS CALL FORWARDING SETTINGS)
Enter *#21# and then tap the Call button. The menu that pops up shows you what your Call Forwarding settings currently are.
CODE 4: *#0*# (OPENS A SERVICE MENU)
When you enter this code, a service menu opens that you can use to test primary functions on your Samsung Galaxy. The test is executed by tapping on the icons. All tests can be ended by pressing the Back key twice. By going through each test, you can determine whether any of the options shown are the reason for the phone not working properly.
CODE 5: *#3282*727336*# (OVERVIEW MENU)
When dialing this code, a menu opens that gives you an overview of the call log, the phone’s internal space, the SD card’s space, the number of contacts and messages, what type of ring tone and wallpaper is used, and the IMEI number.