Midea V4 Plus S Series - Communication Malfunction Betw. Main Control Chip;Inverter Driver Chip

MCAC-VTSM-2015-09 R410A All DC Inverter V4+S Series 60Hz
Troubleshooting 139
4.7 xH0: Communication malfunction between main control chip and inverter driver chip
4.8 H1: Communication malfunction between main control chip and communication chip
The error will only display on faulty unit, all the ODUs will be on standby.
Note:
* How to check for transformer power supply
Check the voltage of 22(CN19), 8(CN30) and 9(CN29) terminals. The normal voltage of 8(CN30) and 9(CN29) terminals should
be 220V, the voltage between “GND” and “5V” of 22(CN19) terminal should be 5V, the voltage between “GND” and “12V of
22(CN19) terminal should be 12V. If the voltage is out of the range, the power supply for main PCB and transformer is abnormal.
* How to check for transformer
The voltage between upper tow pins of 25(CN12) terminal is AC 13.5V; the voltage between under tow pins of 25(CN12) terminal
is AC 9V. The voltage between upper tow pins of 28(CN15) terminal is AC 14.5V; the voltage between under tow pins of 28(CN15)
terminal is AC 14.5V
Outdoor main PCB is damaged
Replace the outdoor main PCB
xH0/H1
Power supply for main PCB and
transformer is abnormal
*
The transformer is damaged
*
Remove the interference
There is electromagnetic interference
near the unit, such as high-frequency
transmitter or other high strength
radiation device etc.
Replace the transformer
Provide normal power supply
No
No
No
Yes
Yes
Yes
17(CN15): Power output
of No.2 transformer
16(CN12): Power output
of No.1transformer
13.5V
9V
14.5V
16V