WARNING: Codes given here are not for fun and use them only if you know exactly what you are going to do!!
First up are some General codes, common to almost all the Nokia mobiles. To use the code just enter it at the standby screen (Just like you dial the numbers to call but here you don’t need to press the dial key):
1. *#06# – This code shows IMEI (International Mobile Equipment Identity) Number of the phone. IMEI is in the format XXXXXX XX XXXXXX X or (TAC FAC SNR SP)
TAC is Type Approval Code (first 2 digits denote Country code)
FAC is Final Assembly Code: These are (10,20 for Nokia) (40,41,44 Siemens) (30 Ericsson) (51 Sony, Siemens, Ericsson) (70 Sagem) (80 Philips) (85 Panasonic)
SNR is Serial Number and SP is Spare (Always Zero)2. *#92702689# [*#war0anty#]
This code opens a menu with following items (May vary from model to model):
a. Displays Serial Number.
b. Displays the Month and Year of Manufacture
c. Displays (if entered) the phone purchasing date
d. Displays the date of the last repair – if entered
e. Shows the total talk time of the phone in Hours:Minutes format. This counter is not reset even if you “Clear timers” through the call register or Log. In some newer phones this code only displays “Life Timer” in hours.
3. *#2820# – Shows the Bluetooth Device Address
4. *#7370925538# (*#res0wallet#) – This code Resets the mobile wallet code but also erases all wallet data.
5. *#0000# or *#9999# – This code shows the Firmware (Phone’s generic software) version
6. Signal and call rate related codes (Network Provider Dependent)
*3370# – Enchanced full Rate Codec (EFR) activation. Phone will automatically restart.
#3370# – Enchanced full Rate Codec (EFR) deactivation
*4720# – Half Rate Codec activation. Phone will automatically restart.
#4720# – Half Rate deactivation code
Enchanced Full Rate (EFR) gives much better sound quality. The new Enhanced Full Rate CODEC adopted by GSM uses the ASELP (Algebric Code Excitation Linear Prediction) compression technology. This technology allows better voice quality in the same number of bits in comparison to the older Full Rate CODEC. However talk-time is reduced by about 5%.
7. *#746025625# [*#sim0clock#] – SIM Clock Stopping code, checks if the SIM clock can be stopped. SIM clock stop is a type of stand-by mode which saves battery time. It will tell you if it can be stopped or not.
Checkout the codes for Nokia 1600 screen upside down trick here.