How do I fix error code MAIN-INVERTER-COMM-ERROR on a Samsung refrigerators?

1. undefined: Inspect wiring harness between main PCB and inverter PCB for damage or loose connections 2. undefined: Use oscilloscope to verify communication signal 3. undefined: Replace inverter PCB first; if issue continues, replace main PCB

Samsung Refrigerators2020–present

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

Inverter PCBMain PCBHarness cable

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

This Error Applies To

Samsung RF28T5 Series Refrigerators (2020) (2020–present)

Service manual exact match: RF28T5101SR/AAService manual exact match: RF28T5A01S9/APService manual exact match: RF28T5021S9/EMService manual exact match: RF28T5001S9/MLService manual exact match: RF28T5021B1/COService manual exact match: RF28T5A01SR/AAService manual exact match: RF28T5021SR/AAService manual exact match: RF28T5001SR/AA