NOKIA
*3370# (efr0) : kich hoat che do EFR, cho chat luong am thanh tot hon nhung ton pin hon.#3370# (efr0) : tat che do EFR neu da bat, may se khoi dong lai.
*4720# (hrc0) : kich hoat che do HRC, chat luong am thanh kem nhung it ton pin hon.
#4720# (hrc0) : tat HRC neu co dung, khoi dong lai may.
*#0000# : thong tin phan mem (phien ban, NSX, ten phan mem).
*#7760 (srn0) : xem so seri.
*#06# : xem IMEI.
*#92702689# (war0anty) : cac thong tin bao hanh.
*#746025625# (sim0clock) : kiem tra sim xem co che do tiet kiem pin hay khong.
*#7780# (rst0) : khoi dong lai may (can nhap mat khau).
*#7370# :khoi phuc cai dat goc (can nhap mat khau).
*#7370925538# (res0wallet) : luu tru bi mat wallet (phai biet mat ma may).
*#67705646# (opr0logo) : xoa logo mang, du ve mac dinh la ten mang cung cap dich vu.
*#7220# (pca0) : kich hoat che do PCCH tiet kiem thoi gian truy cap gprs (tuy vao mang cung cap dich vu).
*#7230# (pcd0) : tat PCCH, may tu khoi dong lai.
*#2640# : hien thi ma bi mat dang su dung.
*#2820# : hien thi bluetooth.
*#7489# : hien thi man hinh bao ve.
*#3925538# : xoa bo chi tieu.
x# : xem so thue bao vi tri x trong the sim (x tu 1-255).
#pw+1234567890+1# hoac +2#, +3#, +4#, +5#, +6#, +7# : kiem tra co khoa hay khong.
#pw+xxxxxxxxxxxxxxx+1# hoac +2#, +3#, +4#, +5#, +6#, +7# : mo khoa ma symbian.
>>Format may symbian s60: Tat nguon roi an giu dong thoi cac phim *, 3, goi di va nut tat mo nguon. Cac giu lieu luu tru trong bo nho dien thoai se bi xoa.
(Ma bao ve mac dinh cua Nokia: 12345).
SAMSUNG
*#9998*help# : truy cap menu tro giup.
*#7465626# : tinh trang khoa may.
