*#06# displays the IMEI and Serial Number.IMEI is sometime called International Mobile Equipment Identity and this is a unique number given to every single mobile phone, typically found behind the battery. You can visit https://www.imei.info and with this number check information about your device.
*#1234#Firmware version - you can check here your SAMSUNG Galaxy A71 Firmware Version and Model Name.
*#0*#Test Menu - in this Test Menu you can test most futures your SAMSUNG Galaxy A71 have, like LCD Display,Touch,LED light,Front and Back Cameras and much more.
*#2683662#Advanced Service Mode - this code gives you to many things in your SAMSUNG Galaxy A71 e.g. can test things like, LTE Wi-Fi etc. also lots of things to be checked SIM Information, Antenna, All SW, IMEI and much more enjoy!
*#0228#Battery Status - here you have every information about SAMSUNG Galaxy A71 battery.
*#0808#USB Settings - by this can change the way your SAMSUNG Galaxy A71 will be by PC/Laptop when you connected with USB cable. Modes like Mass Storage,MPT,ADB, etc...
*#2663#Advanced Firmware Version menu allows you to check TSP FW Version, Touch key FW version, MCU/BINFW Version and Wi-Fi Version.