Summary: As we all know, in winter and summer, air conditioners generally need heating and cooling almost every day, so long-term use will inevitably cause some minor problems. Many failures are caused by damaged air conditioner PCBs. So, what are the maintenance methods for common faults of air conditioner PCB? What are the precautions for air conditioning circuit board maintenance?
(1) If there is a problem with the power supply circuit of the air conditioner PCB, it will be displayed in the form of a blown fuse, which directly indicates that the circuit is short-circuited.
(2) The resistance value can be detected with the ohm plug of the multimeter to judge the short circuit part of the FS technology. After finding the short-circuit part, please replace and repair it in time.
2. FS Technology uses temperature detection circuit:
(1) When the temperature of the thermistor is low, the resistance value is large; on the contrary, the higher the temperature, the smaller the resistance; the resistance value of 25 degrees is about 5-20.
(2) It can be measured with the ohm plug of the multimeter. If the measured resistance value is small or infinite, it proves that the thermistor is damaged and must be replaced immediately.
3. Receiver circuit:
(1) Use the DC acceleration of the multimeter to directly measure the ground voltage of the power supply terminal and the signal terminal of the receiving terminal. The normal electrode value is +5 volts and the signal electrode voltage is +2.5 volts.
(2) If the value is wrong, it should be that the receiving head is damaged or the capacitor is defective. Remove them one by one and find out how to maintain them.
4. The crystal oscillator circuit of FS Technology:
(1) After the air conditioner is turned on, use a multimeter to measure the voltage of the two pins of the quartz crystal oscillator, the value is about +2.2 volts; if it is lower than 1.5 volts, the circuit has a problem of stopping vibration.
(2) The quartz crystal tube can be removed and judged by the ohm plug of the multimeter. If it shows an open circuit, it means that the quartz crystal tube is good; if it is a short circuit, the crystal is damaged.
The three conditions of power supply voltage +5V, reset voltage and clock pulse signal are necessary conditions for the normal operation of the CPU of the circuit board, otherwise the CPU will not work normally. Therefore, a multimeter can be used to detect the voltage of its working state. If the voltage value is normal and the whole machine does not work, it can be judged that the CPU chip is damaged. If the CPU fails, just replace the CPU.