Troubleshooting Guide

Troubleshooting 40
8.8 PC 40 (Communication malfunction between IPM board and outdoor main board
diagnosis and solution)
Description: The main PCB cannot detect the IPM board.
Recommended parts to prepare:
• Connection wires
• Outdoor PCB
• IPM module board
• Electric control box
Troubleshooting and repair:
Communication malfunction between
IPM board and outdoor main board
Is there at least one LED in
the IPM board light?
Check the signal wire
between the IPM board and
the main board, is it
connected good?
Reconnect and retry.
Is error still displayed?
Replace IPM board, and then
check whether the system
can run normally
Replace the electric control
box
No
No
No
No
Yes
Problem is solved
No
Yes
Replace outdoor main board,
and then check whether the
system can run normally
No
Yes
Yes