1. There are many issues that we need to pay attention to when repairing air conditioning circuit boards. First, let's understand the relevant matters that need to be paid attention to in terms of wire width. Due to the transient current generated on the printed lines of the PCB circuit board, the impact interference is mainly caused by the inductance component of the printed wires. Therefore, the inductance of the printed wires should be minimized as much as possible. Adopting the correct wiring strategy and using equal routing can reduce wire inductance, but increase mutual inductance and distributed capacitance between wires. If the layout allows, it is best to use a cross shaped mesh wiring structure. The specific method is to lay the wiring horizontally on one side of the printed board and vertically on the other side, and then connect them with metalized holes at the cross holes.
2. Due to the potential crosstalk issues between PCB circuit board wires, in order to suppress such incidents, it is advisable to avoid long-distance equal routing and to widen the distance between wires as much as possible during the design and wiring process. Signal lines, ground lines, and power lines should not cross as much as possible. Setting a grounded printed line between some signal lines that are highly sensitive to interference can effectively suppress crosstalk.
3. In the actual maintenance of air conditioner computer board faults, the principle of easy first and difficult later should be followed. First, check the power circuit and reset circuit, then replace the crystal oscillator, then check the remote control receiving circuit, and finally replace the CPU. Because replacing multiple CPU pins is the most difficult and expensive, and more importantly, the probability of CPU damage is quite low, so do not easily replace the CPU in the microcomputer control circuit.