LG GR-K20SVZ Technical Manual page 31

MICOM Function and Description of Circuit
11) Communication circuit between Main PCB and Display PCB (LCD type only.)
This circuit provides communication between the MICOM on the MAIN PCB and the MICOM of
the DISPLAY PCB and controls the LCD. If there is no communication between these boards
for 30 seconds, a communication error occurs.
MAIN PCB
MAIN MICOM
DV 12V
GND
SEND (Error state)
RECEIVE (Notch state)
PCB(PWB) ASSEMBLY, DISPLAY
32
DISPLAY PCB
DISPLAY MICOM