Following codes are for Samsung D500, it might work for e720/E730(

Following codes are for D500, it might work for e720/E730(though it is dependent on phones firmware).

*#1111# S/W Version
*#1234# Firmware Version
*#2222# H/W Version
*#8999*8376263# All Versions Together

*#8999*8378# Test Menu
*#4777*8665# GPSR Tool
*#8999*523# LCD Brightness
*#8999*377# Error Menu
*#8999*327# EEP Menu
*#8999*3825523# Don’t Know.
*#8999*667# Debug Mode
*#92782# PhoneModel (Wap)
#*5737425# JAVA Mode
*#2255# Call List
*#232337# Bluetooth MAC Adress
*#5282837# Java Version

#*4773# Incremental Redundancy
#*7752# 8 PSK uplink capability bit
#*7785# Reset wakeup & RTK timer cariables/variables

#*7200# Tone Generator Mute
#*3888# BLUETOOTH Test mode
#*7828# Task screen

#*#8377466# S/W Version & H/W Version
#*2562# Restarts Phone
#*2565# No Blocking? General Defense.
#*3353# General Defense, Code Erased.
#*3837# Phone Hangs on White screen
#*3849# Restarts Phone
#*3851# Restarts Phone
#*3876# Restarts Phone
#*7222# Operation Typ: (Class C GSM)
#*7224# !!! ERROR !!!
#*7252# Operation Typ: (Class B GPRS)
#*7271# CMD: (Not Available)
#*7274# CMD: (Not Available)
#*7337# Restarts Phone (Resets Wap Settings)
#*2787# CRTP ON/OFF
#*2886# AutoAnswer ON/OFF
#*3737# L1 AFC
#*5133# L1 HO Data
#*7288# GPRS Detached/Attached
#*7287# GPRS Attached
#*7666# White Screen
#*7693# Sleep Deactivate/Activate
#*7284# L1 HO Data
#*2256# Calibration info? (For CMD set DEBUGAUTONOMY in cihard.opt)
#*2286# Databattery
#*2527# GPRS switching set to (Class 4, 8, 9, 10)
#*2679# Copycat feature Activa/Deactivate
#*3940# External looptest 9600 bps
#*4263# Handsfree mode Activate/Deactivate
#*4700# Please use function 2637
#*7352# BVMC Reg value (LOW_SWTOFF, NOMINAL_SWTOFF)
#*2558# Time ON
#*3370# Same as 4700
#*3941# External looptest 115200 bps

#*5176# L1 Sleep
#*7462# SIM Phase
#*7983# Voltage/Freq
#*7986# Voltage
#*8466# Old Time
#*2255# Call Failed
#*5187# L1C2G trace Activate/Deactivate
#*5376# DELETE ALL SMS!!!!
#*6837# Official Software Version: (0003000016000702)
#*7524# KCGPRS: (FF FF FF FF FF FF FF FF 07)
#*7562# LOCI GPRS: (FF FF FF FF FF FF FF FF FF FF FF FE FF 01)
#*2337# Permanent Registration Beep
#*2474# Charging Duration
#*2834# Audio Path (Handsfree)
#*3270# DCS Support Activate/Deactivate
#*3282# Data Activate/Deactivate
#*3476# EGSM Activate/Deactivate
#*3676# FORMAT FLASH VOLUME!!!
#*4760# GSM Activate/Deactivate
#*4864# White Screen
#*5171# L1P1
#*5172# L1P2
#*5173# L1P3
#*7326# Accessory
#*7683# Sleep variable
#*8465# Time in L1
#*2252# Current CAL
#*2836# AVDDSS Management Activate/Deactivate
#*3877# Dump of SPY trace
#*7728# RSAV
#*2677# Same as 4700
#*3797# Blinks 3D030300 in RED
#*3728# Time 2 Decod
#*3725# B4 last off
#*7372# Resetting the time to DPB variables
#*7732# Packet flow context bit Activate/Deactivate
#*6833# New uplink establishment Activate/Deactivate
#*3273# EGPRS multislot (Class 4, 8, 9, 10)
#*7722# RLC bitmap compression Activate/Deactivate
#*2351# Blinks 1347E201 in RED
#*4472# Hysteresis of serving cell: 3 dB
#*2775# Switch to 2 inner speaker
#*9270# Force WBS
#*7878# FirstStartup (0=NO, 1=YES)
#*3757# DSL UART speed set to (LOW, HIGH)
#*8726# Switches USBACM to Normal
#*8724# Switches USBACM to Generator mode
#*8727# Switches USBACM to Slink mode
#*8725# Switches USBACM to Loop-back mode
#*3838# Blinks 3D030300 in RED
#*2077# GPRS Switch
#*0277# GPRS Switch
#*22671# AMR REC START
#*22672# Stop AMR REC (File name: /a/multimedia/sounds/voice list/ENGMODE.amr)
#*22673# Pause REC
#*22674# Resume REC
#*22675# AMR Playback
#*22676# AMR Stop Play
#*22677# Pause Play
#*22678# Resume Play
#*77261# PCM Rec Req
#*77262# Stop PCM Rec
#*77263# PCM Playback
#*77264# PCM Stop Play
#*2872# CNT
*#8999*364# Watchdog ON/OFF
#*8370# Tfs4.0 Test 0

#*36245# Turns Email TestMenu on.

*2767*22236245# Email EPP set (….)!
*2767*837836245# Email Test Account!
*2767*29536245# Email Test2 Account!
*2767*036245# Email EPP reset!
*2767*136245# Email EPP set (1)!
*2767*736245# Email EPP set (7)!
*2767*3036245# Email…

*2767*3855# = E2P Full Reset
*2767*2878# = E2P Custom Reset
*2767*927# = E2P Wap Reset
*2767*226372# = E2P Camera Reset
*2767*688# Reset Mobile TV
#7263867# = RAM Dump (On or Off)
*2767*49927# = Germany WAP Settings
*2767*44927# = UK WAP Settings
*2767*31927# = Netherlands WAP Settings
*2767*420927# = Czech WAP Settings
*2767*43927# = Austria WAP Settings
*2767*39927# = Italy WAP Settings
*2767*33927# = France WAP Settings
*2767*351927# = Portugal WAP Settings
*2767*34927# = Spain WAP Settings
*2767*46927# = Sweden WAP Settings
*2767*380927# = Ukraine WAP Settings
*2767*7927# = Russia WAP Settings
*2767*30927# = GREECE WAP Settings
*2767*73738927# = WAP Settings Reset
*2767*49667# = Germany MMS Settings
*2767*44667# = UK MMS Settings
*2767*31667# = Netherlands MMS Settings
*2767*420667# = Czech MMS Settings
*2767*43667# = Austria MMS Settings
*2767*39667# = Italy MMS Settings
*2767*33667# = France MMS Settings
*2767*351667# = Portugal MMS Settings
*2767*34667# = Spain MMS Settings
*2767*46667# = Sweden MMS Settings
*2767*380667# = Ukraine MMS Settings
*2767*7667#. = Russia MMS Settings
*2767*30667# = GREECE MMS Settings

*#7465625# = Check the locks
*7465625*638*Code# = Enables Network lock
#7465625*638*Code# = Disables Network lock
*7465625*782*Code# = Enables Subset lock
#7465625*782*Code# = Disables Subset lock
*7465625*77*Code# = Enables SP lock
#7465625*77*Code# = Disables SP lock
*7465625*27*Code# = Enables CP lock
#7465625*27*Code# = Disables CP lock
*7465625*746*Code# = Enables SIM lock
#7465625*746*Code# = Disables SIM lock
*7465625*228# = Activa lock ON
#7465625*228# = Activa lock OFF
*7465625*28638# = Auto Network lock ON
#7465625*28638# = Auto Network lock OFF
*7465625*28782# = Auto subset lock ON
#7465625*28782# = Auto subset lock OFF
*7465625*2877# = Auto SP lock ON
#7465625*2877# = Auto SP lock OFF
*7465625*2827# = Auto CP lock ON
#7465625*2827# = Auto CP lock OFF
*7465625*28746# = Auto SIM lock ON
#7465625*28746# = Auto SIM lock OFF

**NB:*#8999*228# or *#9998*228# will show you how much charge the battery has in %. It even gives the temperature.