Product Name: PA / RF IC – Redmi 6 / 6A (77638-21)

Compatible Models: Xiaomi Redmi 6, Redmi 6A

Part Type: Power Amplifier / Radio Frequency IC

Function: Manages network signal reception and transmission

Includes: Single 77638-21 IC chip

Alternative Compatible: Can be replaced with 77643-21 if original not available

Usage: Replaces faulty PA IC causing no signal or network issues