*#06# for checking the IMEI (International Mobile Equipment Identity)
*#0000# to reset the phones menu-language to English.
>*<<*<* for checking the firmware revision information (software release)
>*<<*<*> 1-row text strings. if pressing yes you can check the phones text programming in currently selected language. (298 entries)
>*<<*<*>> n-row text strings. if pressing yes you can check the phones text programming in currently selected language. (160 entries?)
The Service Provider (SP) Lock menu is used to lock the cell phone to the SP’s SIM card. Once the cell phone is locked to a specific operator, if one inserts a SIM card from a different operator the phone will refuse to accept it! The cell phone will however accept another SIM card from the same operator.
To activate/deactivate this lock one needs a special secret code that is not available to the end user. (not even to you… or is it ? in case please let me know!)
<**< Lock to Network? if pressing yes you have 5 attempts to enter NCK.
<**<< Lock to Network subset? if pressing yes you have 5 attempts to enter NSCK.
Warning: Your phone can be locked to a service provider FOREVER by doing this! If an invalid code is entered all five times, the menu will exit and be deactivated! Any further attempt to activate the NCK/NSCK lock Menu will result in the response "Not allowed"! However the NCK/NSCK lock can be recover through a direct clearing in the EEPROM.
Shortcut for Last Dialed call menu…
If you for some reason don’t want to enter the ‘Last Dialed calls menu’ by using the ‘YES’ key you can use the following key stroke instead: First ‘0’ then ‘#’.
Access menu without Sim card …
To access to the menu in your phone without having a card inside do the following: type **04*0000*0000*0000# When display say "Wrong Pin" press NO and you have access to the all menus: Info, Access, Settings, Calculator, Clock, Keylock On?, Mail, Phone book. NOTE if you try this on the GH688 your phone may stop at Keylock On? menu and you´ll have to take your battery out to turn the phone on again.