1.Điện thoại Nokia *3370# (efr0) : kich hoat che do EFR, cho chat luong am thanhtot hon nhung ton pin hon. #3370# (efr0) : tat che do EFR neu da bat, may se khoi dong lai. *4720# (hrc0) : kich hoat che doHRC, chatluong am thanh kem nhung it tonpin 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 tukhoi dong lai. *#2640# : hien thi ma bi mat dang su dung.*#2820# : hien thi bluetooth.*#7489# : hien thi man hinh baove. *#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 dienthoai se bi xoa. (Ma bao ve mac dinh cua Nokia: 12345). 2.điện thoại samsung *#9998*help# : truy cap menu tro giup. *#7465626# : tinh trang khoa may. *#7337# : unlock cho dien thoaidoi moi.*2767*java# : khoi tao java, xoa java dang co. *2767*media# : xoa nhac, hinh. *2767*wap# : khoi tao lai thongso wap.*2767*cust# : tao lai phan mem tu EEPROM. *2767*full# : tra lai tinh trang xuat xuong.*#9998*java# : menu cac tinh nang tuong thich java.*#9999*0# : che do man hinh.*#9999# : phien ban firm ware.*#0837# : thong tin cau truc phan mem. *#8888# : phien ban phan cung. *#9998*746# : thong tin ve sim. *#9998*778# : hien thi bang dich vu sim.*#0523# : do tuong phan.*#0842# : chuyen sang che do rung. *#0288# : thong tin tinh trang pin. *#8999*228# : thong so ly thyetcua pin. *#9998*377#: xem danh sach cac loi.*#9998*782# : hien thi lich va dong ho bao thuc. *#9998*585#: thong tin vung bo nho cam truy cap (NNM). *#3243948# : tat tinhnang chong nhieu am thanh.*#0001# : hien thi thong so ve ket noi serial. *0001*s*f*t# : thaydoi cac thong so cua ket noi serial (s = toc do; f = 0, 1; t = 0, 1).*#9125# : bieu tuong mat cuoi khi sac pin. *#8999*246# : tinh trang ung dung. *#8999*289# : thay doi tan so chuong bao thuc.*#8999*324# : man hinh sua loi(dung cho KTV). *#8999*364#: bat tinh nang theo doi he thongWATCHDOG - mot ung dung java.*#8999*427# : xem thong tin doWATCHDOG cung cap.*#8999*523# : thay doi tuong phan man hinh LCD.*#8999*636# : tinh trang bo nho. *#8999*764# : dung luong cua sim. Mot cach kiem tra xem ban dang dung super sim hay khong(super co dung luong 64k).*#8999*842# : kiem tra tinh nang rung cua dien thoai.*#8999*862# : hien thi mot so tinh nang khi dung dien thoai voicarkit. *#8999*999# : lan kiem tra cuoicung. *#8999*9266# : mot man hinh sua loi khac.*#8999*638# : hien thi thong tinve mang cua nha cung cap dich vu ma ban dang su dung.*#9998*5646# : thay logo khoi dong. *#9998*76# : xem ma so san pham. *#9998*968# : giai dieu dang duoc dung cho tinh nang bao thuc. (Ma bao ve mac dinh cua Samsung: 1111) 3.điện thoại sony ericsson >*<<*<* : xem menu (< : sang trai, > : sang phai). <**< : thong tin ve simlock. *#7353273# : kiem tra phien ban phan mem (thao sim)*#04*0000*0000*0000# : mo dien thoai khi khong co sim. 0# : so dien thoai goi cuoi 4.diện thoại motorola *#300#ok : xem phien ban phan mem. *#301#ok : kiem tra ban phim. *#303#ok : chuyen sang tieng Anh. *#304*19980722#ok: bat Engineering mode.*#304#ok : tat Engineering mode. *#307#ok : kiem tra Engineering mode. *#311#ok : doi code mac dinh cua may.*#400#ok : ADC, CAL, VAL (???).*#402#ok : chinh do tuong phan. *#403#ok : thong tin nha san xuat. *#302#ok : kiem tra Acoustic. *#19980722#ok : quanly mat khau. 5.Điện thoại philips *#8377*# : hien thi phien ban phan mem.*#3333*# : hien thi danh sach bi khoa. *#7489*# : hien thi ma bi mat 6.Điện thoại tàu *#66*# : mo menu. *#3646633#: mo menu kiem tra loi.*#0000#ok : chuyen sang tieng Anh. *#0086#ok : chuyen sang tieng Trung Quoc. *#0084#ok : chuyen sang tieng Viet.