Midea R32 M thermal Arctic Mono fault F1

What it means

DC bus voltage is too low (serial number 116)

Likely causes

1. The DC bus voltage is too low.
2. Power supply malfunction, loose power connections, capacitor failure, inverter issue
3. Hydronic box main PCB fault
4. Damaged cables between hydronic box main PCB and outdoor unit main PCB
5. Outdoor unit main PCB fault
6. Incorrect or abnormal input power supply (N or L)

Where to start

1. Step 1: Check if power supply is abnormal. If yes, provide normal power. Step 2: Check if LED light is OK. If yes, check if voltage of PN is 380V. If PN voltage is 380V, check the main board. Step 3: If LED light is not OK, check if IGBT voltage is correct. If IGBT voltage is not correct, the inverter board is damaged, change it. Step 4: If IGBT voltage is correct, check the rectifier bridge.
2. Check IGBT voltage.
3. Verify LED light is OK. Measure PN voltage.