Zero-Crossing Signal Error Diagnosis And Solution - Pioneer YN018GMFI16M2D Service Manual

9.4.1.3 zero-crossing signal error diagnosis and solution.

Malfunction decision
conditions
Supposed causes
Trouble shooting:
When PCB does not receive zero crossing signal feedback for
4 minutes or the zero crossing signal time interval is abnormal.
● Connection mistake
● PCB faulty
PIC3 :Main board LED when power on and unit
standby.
PIC 4: Check point button, press 1 time for check
how many indoor units are
connected.( YN027GMFI16M3D)
Check point button, press 18 times for check how
many indoor units are connected.(for Others)