R410A All DC Inverter Mini VRF MCAC-VTSM-2016-02
66 Troubleshooting
4.3 H0: Communication malfunction betweem IR341/main board
Communication malfunction between outdoor PCB
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 portās 3 and 4 pillar, check whether it is 5V,
(the third pillar on the main board labels +5V)
Replace outdoor main board.
Check whether the connecting wiring between the
IPM module positive pole and the CN12 on the power
board is break off
Insert the connecting wiring well over
again
Check whether the connecting wiring
between the IPM module and the CN1 on
the main board is break off
Insert the connecting wiring well over again
Use the multi-meter to measure whether the voltage
between the P and the N on the power board is between
Check whether the indicator lights LED on
the main board are flashing
Replace the outdoor main board