Y1
CSTCE16M0V53-R0
Crystal
3-pad SMD ceramic resonator (CSTCE series)
Clock crystal
About this component
Provides one of the two 16 MHz clocks on the board, one for the ATmega2560 and one for the ATmega16U2. A failed clock part stops its MCU completely: no sketch runs, or the board disappears from USB. Arduino's product page describes the main clock as a 16 MHz crystal oscillator, so check the board before ordering a replacement. Part variants: The Rev3 schematic shows two 16 MHz clock parts: Y1 (Murata ceramic resonator CSTCE16M0V53-R0) and a second 16 MHz part Y2 whose value could not be read; which one clocks which MCU was not confirmed.
What it does on this board
16MHz clock for the main MCU.
Pinout & readings
No pinout or reference readings yet — these show what each pin does and what a healthy part should measure.