Error Code MAIN-INVERTER-COMM-ERROR
Compressor inverter board and main board have lost communication
Moderate
Address soon - your appliance may not work properly
Also displayed as: F and R blink (main-inverter communication error — item 43 in self-diagnosis list)
What This Means
Loose or damaged wiring between main PCB and inverter PCB; Failed inverter PCB; Failed main PCB communication driver circuit
What actually causes this:
The electronic boards controlling the compressor are not talking to each other — the compressor will not run and the unit will not cool.
First Thing to Check
Unplug the refrigerator for 30 seconds then restore power — do not touch any internal components.
Parts Involved
How to Fix
- 1
Inspect wiring harness between main PCB and inverter PCB for damage or loose connections
- 2
Use oscilloscope to verify communication signal
- 3
Replace inverter PCB first; if issue continues, replace main PCB
Other Error Codes for RF28T5021S9
Refrigerator compartment temperature sensor is disconnected or dead
Internal humidity sensor has failed or is disconnected
Defrost sensor on freezer evaporator is failed or disconnected
Freezer fan motor is not running or not sending feedback
Supply voltage to compressor is too high
Freezer temperature sensor is failing or disconnected
Ice maker temperature sensor in freezer is failed or unplugged
External room temperature sensor is failed or disconnected