S4 LTE-A Secret Codes

*#06# --> IEME number
*#03# --> Nand Flash Header Read
*#0*# --> Test screen
*#0283# --> Audio loopback
*#2663# --> Firmware and Update versions
*#12580*369# --> Software and Hardware info
*#0228# --> Battery Status
*#2263# --> RF Band selection
*#9090# --> Service Mode
*#7284# --> UART MODEM PDA
*#8736364# -- > Update Settings
*#7353# --> Quick test menu
*#0011# --> Service menu
*#9900# --> SysDump

S K T Hidden Menu

Using the default dialer, enter the following number: 319712358
Depending on your phone model, enter one of the following password codes:

SKT ---> 996412
KT ---> 774632
LG U+ ---> 0821