U5
Quectel EG25-G
Module
LGA module, 29 x 32 x 2.4 mm
LTE modem
About this component
Schematic U1500. Handles calls, SMS, mobile data and GPS; the A64 talks to it over USB and AT commands, and voice audio goes over PCM. It runs its own firmware, and many 'modem disappeared' problems are fixed by firmware updates or power-cycling via the hardware kill switch rather than by hardware repair. It is an LGA module, soldered down under its own shield.
What it does on this board
Cellular modem module (worldwide LTE bands).
Pinout & readings
No pinout or reference readings yet — these show what each pin does and what a healthy part should measure.