H0: Communication Malfunction Betweem Ir341/Main Board - Midea Mini VRF Technical & Service Manual

R410A All DC Inverter Mini VRF

4.3 H0: Communication malfunction betweem IR341/main board

LED displays E3/H0
Communication malfunction between outdoor PCB
Check whether the indicator lights LED on
the main board are flashing
Check whether
between the IPM module and the CN1 on
the main board is break off
Disconnect the connecting wiring between the IPM
module and the CN1 on the main board, use the
multi-meter to measure the voltage between the IPM
module CN1 port's 3 and 4 pillar, check whether it is 5V,
(the third pillar on the main board labels +5V)
Check whether the connecting wiring between the
IPM module positive pole and the CN12 on the power
board is break off
Use the multi-meter to measure whether the voltage
between the P and the N on the power board is between
277V and 345V
Replace the power board
66
NO
the connecting wiring
NO
NO
NO
NO
YES
Replace the outdoor main board
YES
Insert the connecting wiring well over again
YES
Replace outdoor main board.
Insert the connecting wiring well over
YES
again
YES
Replace the IPM module
MCAC-VTSM-2016-02
Troubleshooting