Midea MSH-07CRN1, MSH-07HRN1, MSH-09CRN1, MSH-09HRN1, MSH-12CRN1, MSH-12HRN1 Manual page 275

5. Failure phenomenon(heat pump)
Failure phenomenon
Over current protection of the compressor occurs 4
times
Indoor fan speed has been out of control for over 1
minute
No over-zero signal
Temp. sensor on indoor evaporator is open circuit or
short circuit
Indoor room temp. sensor is open circuit or short circuit
EEPROM error
r Extinguish
Flash at 5Hz
5.1 Operation lamp flashes ,Timer lamp off and Defrosting lamp flashes.
Operation lamp flashes ,Timer lamp off and Defrosting lamp flashes
After changing the main control board, check if the failure releases
The voltage of power supply is too low (less than 187V)?
5.2 Operation lamp off, Timer lamp flashes and Defrosting lamp flashes.
Is connector connection good?
Yes
Is voltage being applied to the fan motor?
Yes
Fan motor is defective
5.3 Operation lamp flashes, Timer lamp flashes and Defrosting lamp flashes .
This is alarm signal when the main chip can't detect over-zero signal. When such
failure occurs, the main control board must have fault.
No
Yes
Power supply fault
Operation lamp
X
X
X
On
.
No
Outdoor unit fault (such as the compressor)
No
Indoor PCB is defective
3
Timer lamp Defrosting lamp
X
X
Yes
Indoor PCB is defective
No
Repair the connector
X
X