To check the phones Software revision type-
      *#0000#

Information you get from the Software revision-
V 05.31
18-02-99
NSE-3
1ST Line = Software revision
2ND Line = The date of the software release
3RD Line = Phone type

To enter the service menu type-

      *#92702689#
Serial number (IMEI)
Production date (MM/YY)
Purchase date (MM/YY) You can only enter the date once.
Date of last repair (0000=No repair)
Transfer user data to another Nokia phone via Infra-Red
Clock Stopping

EFR CALL QUALITY

To activate EFR (Enhanced Full Rate) Enter the code-
*3370#
This improves call quality but decreases batterylife by about 5%
To deactivate it, Enter the code-
#3370#

THE JAMES BOND TRICK

If you short-circuit theleft middle and right pins on the bottom of the phone with all connections touching each other, the Nokia software hangs! The profile "Headset" will be activated. Before you do this just activate the "Automatic Answer" in the headset profile and set the ringing volume to "Mute". Now you can use your phone for checking out what people are talking about in a room. Just place it under a table in a room and call it. The phone receives the call without ringing and you can listen to what people are saying.

NETWORK MONITOR

There is a hidden menu inside your Nokia phone. If you want to activate it, you'll have to re-program some chips inside of your phone.
Check your software version. You can only continue if you have v4.33, v4.73 or v5.24.
Take apart the phone.
De-solder the EEPROM (ATMEL AT 24C64).
Read out the data with an EEPROM programmer and save it to a file (Backup).
If you have v.33 or v4.73, change the address "03B8" from "00" to "FF".
If you have v5.24 then change the address "0378" from "00" to "FF".
Write the new data to the EEPROM and solder it back to the phone,
Power on your phone and you should have "Netmonitor" enabled.
The Network Monitor gives you the following information
Carrier number

MS RX Level in DBM,  ,Received signal quality  ,  MS TX power level

C1 (Path loss criterion, used for cell selection and reselection). The range is -99 to 99  ,  RTL (Radio link timeout)  ,  Timeslo