The following are the secret codes and tricks for viewing imei and firmaware and for unlocking china and korean mobiles.check the secret codes of china mobiles below
*#66*# Set Factory Mode CONFIRMED
*#8375# Show Software Version CONFIRMED
*#1234# A2DP ACP Mode CONFIRMED
*#1234# A2DP INT Mode CONFIRMED
*#0000# + Send : Set Default Language CONFIRMED
*#0007# + Send : Set Language to Russian CONFIRMED
*#0033# + Send : Set Language to French CONFIRMED
*#0034# + Send : Set Language to Spanish CONFIRMED
*#0039# + Send : Set Language to Italian CONFIRMED
*#0044# + Send : Set Language to English CONFIRMED
*#0049# …

THE METHOD TO UNLOCK SAMSUNG E250
AND E330 IS GIVEN BELOW.IT WORKED FOR ME AND I HOPE IT WILL WORK FOR YOU ALSO.
TESTED THIS ON E250 & E330,
POWER ON PHONE WITHOUT SIM CARD,
INSERT A LOCKED OFF SIMCARD WHILE THE PHONE IS ON,
TYPE *2767*3855#,
THE PHONE WILL REBOOT AFTER ABOUT 1min IN NORMAL MODE WITH THE SIM CARD WORKING. TYPE *7465625*638*00000000*00000000#,
IT SAYS NETWORK LOCK PERSONALIZED,
THEN UNDER SUBSET LOCK WHEN IT REBOOTS JUST TYPE 00000000,
THAT’S ALL UR PHONE IS UNLOCKED.
HOPE IT’S SIMPLE AND UNDERSTANDABLE:)
it worked with me

imagine ur cell battery is very low, u r expecting an important call and u don’t have a charger.
Nokia

instrument comes with a reserve battery. To activate, key is “*3370#”
Ur cell will restart with this reserve and ur instrument will show a 50% incerase in battery.
This reserve will get charged when u charge ur cell next time.
*3370# Activate Enhanced Full Rate Codec (EFR)-Your phone uses the best sound quality but talk time is reduced by approx. 5%
#3370# Deactivate Enhanced Full Rate Codec( EFR)
*#4720# Activate Half Rate Codec – Your phone uses …

Samsung Secret Codes
Software version: *#9999#
IMEI number: *#06#
Serial number: *#0001#
Battery status- Memory capacity : *#9998*246#
Debug screen: *#9998*324# – *#8999*324#
LCD kontrast: *#9998*523#
Vibration test: *#9998*842# – *#8999*842#
Alarm beeper – Ringtone test : *#9998*289# – *#8999*289#
Smiley: *#9125#
Software version: *#0837#
Display contrast: *#0523# – *#8999*523#
Battery info: *#0228# or *#8999*228#
Display storage capacity: *#8999*636#
Display SIM card information: *#8999*778#
Show date and alarm clock: *#8999*782#
The display during warning: *#8999*786#
Samsung hardware version: *#8999*837#
Show network information: *#8999*638#
Display received channel number and received intensity: *#8999*9266#
*#1111# S/W Version
*#1234# Firmware Version
*#2222# H/W Version
*#8999*8376263# All Versions Together
*#8999*8378# Test Menu
*#4777*8665# GPSR Tool
*#8999*523# LCD Brightness
*#8999*377# Error LOG Menu
*#8999*327# …

NOKIA ::. Nokia Universal Codes Code Description :
These Nokia codes will work on most Nokia Mobile Phones
(1) *3370# Activate Enhanced Full Rate Codec (EFR) – Your phone uses the best sound quality but talktime is reduced my approx. 5%
(2)#3370# Deactivate Enhanced Full Rate Codec (EFR) OR *3370# ( Favourite )
(3)*#4720# Activate Half Rate Codec – Your phone uses a lower quality sound but you should gain approx 30% more Talk Time.
(4)*#4720# Deactivate Half Rate Codec.
(5)*#0000# Displays your phones software version, 1st Line : Software Version, 2nd Line : Software Release …