Speaking of air conditioning, I believe that many people must not be unfamiliar, in the summer, air conditioning can create a comfortable environment for us to better study and work, but also greatly reduce the summer brings irritable breath, in the winter, air conditioning can be for us to warm, so that we can also be warm in the winter as spring, when it comes to air conditioning brands, we will recall Mitsubishi Heavy Industries, Panasonic, Daikin, Gree, with the increasing number of air conditioners, air conditioning There will also be a fault, at this time, we should do what? Here let me for air conditioning fault diagnosis and repair of common failures and repair methods to do a detailed introduction it.
1, the air conditioning circuit board power circuit failure.
Inspection method:
Air conditioning circuit board power circuit failure characteristics are generally intact fuse and a power on the burn fuse. For the former fault, use the multimeter AC block to measure the transformer primary and secondary whether there is 220V and 10-13V, if there is, then use the multimeter DC block to measure 7812 and 7805 whether there is +9-12V and +5V voltage, so you can distinguish the fault site. For the latter, indicating the existence of a short circuit, the application of multimeter Ohm block resistance detection to determine the short circuit parts of the circuit. At the same time, you can also use the division method to check, such as by disconnecting the transformer primary winding, power on the test machine, if also burned fuse, that burned fuse is due to the existence of a short circuit in the varistor or porcelain capacitor, otherwise, it is due to the transformer or rectifier tube, etc. short-circuit phenomenon.
2, the air conditioning circuit board temperature-sensing circuit failure
Inspection method:
Thermistor is a negative temperature coefficient of the thermistor, that is, the higher the temperature, the smaller the resistance, the lower the temperature, the greater the resistance, 25 degrees when the resistance value of about 5-20KΩ (varies by model). Thus, the resistance value can be measured with a multimeter ohmic block to determine the good or bad, if the measured resistance value is infinity or very small, indicating that the thermistor has been damaged.
3, the air conditioning circuit board relay circuit failure
Inspection and repair methods:
First of all, distinguish between the set rate driver module damage or relay damage, if the power on by remote control, the buzzer sound, but the machine does not work, generally set rate driver module damage; if the power on, only part of the function is not normal, it is possible that the relay is damaged, at this time can continue to listen to the relay whether the suction sound, to determine the relay is the coil burned or contact sticking, the relay coil burned when There is no suction sound. Relay can also be used to determine the ohmic block multimeter, disconnect the power supply, first measure the coil resistance value, the normal resistance value of several hundred ohms, if infinity or zero, indicating that the relay is damaged; then measure the contacts, if the resistance value of zero indicates that the contacts are sticking.
4, the air conditioning circuit board remote control receiving circuit good failure
Inspection and repair methods:
Power on, use the multimeter DC block to measure the receiving head power supply and signal terminal voltage to ground, the normal value should be the power supply pole +5 V voltage, signal pole voltage of +2.5V. Otherwise, it is not normal. Common failures have received head damage or capacitor breakdown.
5, the air conditioning circuit board reset circuit good fault.
Inspection method:
Reset voltage is a delayed rising voltage, available multimeter DC voltage file for observation, if the observation is not clear, but also available oscilloscope detection, detection with an oscilloscope can have a baseline in the jitter, and then become high, which is the start of the reset voltage process. If you do not see the jitter of the baseline, it means that the reset circuit is faulty.
No matter which electrical furniture, they will have their own start-up mode and the use of efficacy, cell phones it can switch on and off, you can download games, download a variety of apps, computers can open various web pages, you can develop software, so the operation is required through the local mode of operation to complete, and no matter what the machine electronic equipment, they will have a failure, the same air conditioning, I believe Through the above for the air conditioning fault diagnosis and repair of common failures and repair methods can be introduced to enable you to have a great help in the air conditioning when some situations arise.
