Other secret tricks for samsung mobile or cellphone

 If you have downloaded corrupted or incompatible Java midlets or other media,
  which are causing problems with the phone, try this

  *2767*JAVA# Java Reset and (Deletes all Java Midlets)
  *2767*MEDIA# Reset Media (Deletes All Sounds and Pics)
  *2767*WAP# Wap Reset
  *2767*CUST# Reset Custom EEPR0M
  *2767*FULL# Reset Full EEPR0M (Caution)
  For example : *2767*JAVA# would be keyed in as *2767*5282#
  Note : Not all codes will work with SGH-C100.

  The master reset code is:
  #*7728#
  This will not delete anything from your
  mobile phone, but set each and eveything to its
  default/standard setting as it was on the time of purchase.

  To unlock your phone put a sim from another company,
  now type *#9998*3323# it will reset your phone. Push exit and then push 7,
  it will reset again. Put your other sim in and it will say sim lock,
  type in 00000000 then it should be unlocked. Type in *0141# then
  the green call batton and it's unlocked to all networks.
  This code may not work on the older phones and some of the newer phones.
  If it doesn't work you will have to reset your phone without a sim in it
  by typing *#2767*2878# or *#9998*3855# (not tested)

  Other Samsung Codes
  *#9998*4357# Help Menu
  *#9998*5282# Java menu (GRPS/CSD settings for JAVA server)
    *#9999#0# Monitor Mode
  *#9999# or *#9998*9999# Software Version
  *#8888# or *#9998*8888# Hardware Version
  *#9998*746# or *#9998*0746# or *#0746# Sim Infos
  *#9998*523# or *#9998*0523# or *#0523# Display Contrast
  *#9998*842# or *#9998*0842# or *#0842# Vibration On (until you push OK)
  *#9998*289# or *#9998*0289# or *#0289# Buzzer On (until you push OK)
  *#9998*288# or *#9998*0288# or *#0288# Battery & Field Infos
  *#9998*377# or *#9998*0377# Error log
  *#9998*778# or *#9998*0778# or *#0778# Sim Service table
  *#9998*782# show date and alarm clock
  *#8999*638# show network information
  *#9998*5646# change operator logo at startup
  *#9998*76# production number
  *#9998*968# view melody for alarm
  *#9998*585# Non-Volatile Memory (NVM)
  *#3243948# Digital Audio Interference Off
  *#32436837# Digital Audio Interference On