A service call in the middle of summer
On this scorching afternoon in Côte-des-Neiges–Notre-Dame-de-Grâce , a customer contacted us after noticing that their Sharp wall-mounted air conditioner was no longer blowing cold air. The power light remained on, but there was no response from the indoor fan. At AirGreen , we know that an inactive wall-mounted air conditioner can quickly make a space uninhabitable during intense heat.
We therefore dispatched one of our certified technicians to the site for a complete diagnosis and rapid restoration of service .
Initial inspection: a device open and awaiting intervention
Upon arrival, our technician observed that the top cover of the indoor unit had already been removed, exposing the evaporator coil and electronic board. The customer had attempted to clean the filter, without success. The unit still refused to start, despite a start signal from the remote control .
This type of symptom can come from several causes: a damaged electronic card, a defective temperature sensor, or even a problem with the power supply of the display card.
Step-by-step diagnosis
Our AirGreen team always follows a strict protocol to avoid unnecessary part replacements. Here are the steps of our intervention:
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Check the power supply : correct voltage of 120V at the input of the indoor module.
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Check the integrated fuse on the main board: in good condition.
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Continuity test of the cables connecting the display board to the main board: abnormal result – loss of signal on the CN6 connector.
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Inspection of the ambient temperature sensor (thermistor) : stable resistance, therefore not faulty.
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Infrared control module observation : correct response to the remote control signal.
The diagnosis revealed a problem with the power connector on the main board , caused by gradual heating of the terminals - a typical failure on some Sharp models after several years of service.
Repair carried out
Once the diagnosis was confirmed, our technician undertook a careful repair of the connector :
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Complete disconnection of the electronic card.
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Cleaning the oxidized terminals and replacing the CN6 connector with a high heat resistance model.
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Checking electrical continuity after replacement .
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Reinstall the top cover and replace the cleaned filters.
After turning the power back on, the wall-mounted air conditioner turned back on immediately. The indoor fan resumed rotation , and the evaporator began cooling within minutes.
Tests and results
To ensure the system was working properly, we carried out a series of measurements:
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Blown air temperature : 10.8°C after 10 minutes of operation.
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Defrost cycle : normal.
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Power consumption : in accordance with manufacturer's nominal values.
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Quiet operation : no vibration or abnormal noise.
The customer immediately felt a rapid return of thermal comfort , and highlighted the precision of our explanations concerning the cause of the problem and the maintenance actions to be taken.
Tips to avoid this type of breakdown
The electronic boards in Sharp wall-mounted air conditioners are sensitive to heat and dust. To extend their lifespan, we recommend:
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A complete annual maintenance by an AirGreen professional before the summer season.
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Regular cleaning of the filters every two to three weeks during the summer.
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Avoid disassembling the front panel yourself to avoid damaging the fragile connectors.
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Watch for warning signs : flashing light, slow response to remote control, or non-start relay noise.
AirGreen: HVAC expertise serving Montrealers
This intervention in Côte-des-Neiges–Notre-Dame-de-Grâce once again demonstrates our commitment to providing fast, precise and professional service to all our clients in Greater Montreal, Laval, Longueuil, the North Shore and the South Shore .
At AirGreen , every service call is treated as a priority. Our technicians are trained on all major brands— Sharp, Fujitsu, Gree, Midea, LG, Trane, Zephyr, Goodman —and have the parts you need to get your unit up and running on the first visit.
AirGreen – Performance and reliability, at the heart of every HVAC repair.