*#06# for checking the IMEI (International Mobile Equipment Identity)
>*<<*<* 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
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.
Here is how to activate the menu:
<**< 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 ‘#’.
Bat. level indicator when turned OFF
When the phone is turned off and the phone is not changing – the bat. level can be seen for a short period of time by pressing the ‘NO’ key quick once (it has to be quick!) and then wait for about 2 sec. The bat. level will now be shown in the display at its normal position.
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 your phone may stop at Keylock On? menu and you´ll have to take your battery out to turn the phone on again.
Free phone calls using the GF788
This trick has only been reported working on PREPAID GSM CARDS and in some countries and with some sw versions.
The prepaid GSM SIM CARD is a kind of "SIM card" which only has a sertant amount of credit on it (like a normal phonebox telecard)… if it can be traced? – we don’t know…
Well..here’s the trick you dial the no. normally and press YES. While "connecting" is shown on the screen, the following procedure should be carried out: Press CLR then 0 then # and then NO (twice) so as to switch OFF the phone. You can then still speak on the phone while it is switched off but the SIM card does not record your calls which will lead to FREE phone calls in some countries.. we hope!!
Another variant of the code
Make a Call, while the phone says Connecting type 083# (the position 83 must be empty! ), when phone says Pos Emtpy, press the NO key and turn off the phone.
If you can make the call with the phone turned off you will face a problem when you need to hang up the phone…the only way for you to do that is remove the battery…???