LG Refrigerator Error Code Comp Tx Error

The Comp Tx Error on an LG refrigerator indicates a communication failure between the compressor drive PCB (the inverter board that controls the variable-speed compressor) and the main control MICOM (microcomputer) on the refrigerator's primary control board. These two boards exchange data signals continuously so the main control can command compressor speed and receive status feedback. When that communication link breaks down or returns invalid data, the refrigerator flags this error and may suspend compressor operation to protect the system.

The compressor drive PCB and main control board communicate over a dedicated signal line. A fault can originate on either end of that connection. Common hardware-level causes include a failed inverter board, a defective main control board, or damaged wiring in the harness that runs between them. Power instability, such as a brief surge or dropout, can also corrupt the communication temporarily without causing permanent component damage.

The first diagnostic step involves checking whether the condenser fan (C-Fan) is running and whether the compressor is operating. If both are stopped alongside the error, a power reset should be performed by unplugging the unit for several minutes and then restoring power. If the error clears and normal operation resumes, the fault was likely a transient power or signal issue. If the error returns immediately or shortly after the reset, a component failure in one of the two PCBs or the interconnecting wiring harness is the probable cause, and board replacement will be required.