Nokia is one of the most popular phones used worldwide. Below are some secret codes which can be helpful incase you encounter some one or two problems with yours. Just specify your problem and try the below codes.
*#06# for checking the IMEI (International Mobile Equipment Identity).
*#06# for checking the IMEI (International Mobile Equipment Identity).
*#7780# reset to factory settings.
*#67705646# This will clear the LCD display (operator logo).