Warranty Code:
Dial *#92702689# [*#war0anty#] and this asks warranty code.
You can then type a number of codes to find out different details of your phone:
6232 - Display date of manufacture.
7332 - Display date of last repair.
7832 - Display purchasing date.
9268 - Display serial number.
37832 - Set purchasing date to MMYY.
87267 - Confirm Transfer, Related to firmware upgrades.
