*#7353# Action: Opens a simpler self-test interface. What you can do: Test speaker, receiver, microphone, vibration motor, and the IR LED (if your A7 variant has it). Exit: Press "Back" or "Finish."
Some codes can trigger a factory reset without warning, erasing all your data. Always back up your phone before experimenting. how+to+use+secret+codes+on+samsung+galaxy+a7+2+work
Shows network status, signal strength, and cell information. USB Settings Change USB connection modes (MTP, ADB, etc.). System Dump *#7353# Action: Opens a simpler self-test interface