R-Pro › Field cases › Refrigeration systems
Fan Motor Control Signal Failure (PCB / Relay)
Likely causes
Fan relay contact failure
Check: Check fan relay coil continuity and contact conductivity
What to do: Check fan relay coil continuity and contact conductivity → Measure voltage at PCB fan output terminal → Measure temperature sensor (NTC/PTC) resistance → Replace relay if faulty → Replace PCB if faulty
PCB fan output circuit failure
Check: Measure voltage at PCB fan output terminal
What to do: Measure voltage at PCB fan output terminal → Measure temperature sensor (NTC/PTC) resistance → Replace relay if faulty → Replace PCB if faulty
Fan signal not output from temperature sensor malfunction
Check: Measure temperature sensor (NTC/PTC) resistance
What to do: Measure temperature sensor (NTC/PTC) resistance → Replace relay if faulty → Replace PCB if faulty
Fan motor is OK but the PCB or relay is not sending an activation signal. Inspect relay and PCB.
All 565 cases work offline in R-Pro, with error codes for 62 brands and P-T data for 108 refrigerants.
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