Basic steps of switching power supply maintenance
Before we repair the switching power supply, we need to make preparations. First of all, it needs to be visually inspected. In special cases or when necessary, use a magnifying glass to observe it carefully. It is also important for smelling work. For experienced maintenance personnel, he can judge the location of burned components by smell. And it can accurately determine where the faults of some seemingly intact components are.
The first step is to check the power supply. At this time, we not only need to use a multimeter to detect the value of its voltage, but also use an oscilloscope to detect its voltage waveform.
The second step is to check the crystal oscillator. In this step, we will check whether the crystal oscillator is oscillating. We need to use an oscilloscope to detect the waveform of the crystal oscillator pin.
The third step is to check the reset situation. We can check whether the reset signal is normal or not, and judge whether the reset pulse is correctly transmitted to the CPU chip.
The fourth step is to check the bus. There are many buses here, including data bus, address bus and control bus. As long as there is a problem with one of these buses, it will cause a failure. In such a case, we can use the method of detecting the resistance of the parallel bus to ground to check whether a certain road has a fault. Of course, we can also judge by observing the waveform of each bus.
The fifth step is to check the interface chip, because the damage rate of this device is the highest, we can use replacement or even special instrument detection to judge the fault.
The sixth step is the replacement of components. After the above inspection, we will find that a certain component has failed. At this time, we need to deal with the failure. The way to deal with it is to repair the circuit, replace and transform the device and so on.
The seventh step is to test the power supply. After we have eliminated the fault, we must perform an offline loading test before going to the machine. After the normal detection, it can be loaded on the machine for testing and use.
Through the brief introduction above, have you mastered the basic steps of switching power supply maintenance? For this more professional operation, we still need to be careful, because improper operation may damage more devices. This is often what we don't want to see.
