Kouwa Liquid Tuner 071920170042 is a compressor control unit used in industrial liquid handling systems, typically featuring a PLC‑based drive and motor controller circuitry. Common failure modes for this class include power supply voltage drops or spikes, failed MOSFETs/IGBTs on the drive board, shorted or burned-out relays, and degraded PCB traces from moisture ingress; overheating of the compressor motor can also trigger thermal protection shutdowns. Initial troubleshooting should verify that the unit receives its rated input voltage and correct polarity, inspect all fuses and circuit breakers for continuity, and visually check the drive board for burn marks, cracked components, or loose solder joints before proceeding to diagnostic software checks for error codes.[oss-gpt-20b]