Basic Steps for Repairing Switching Power Supplies
We still need to make preparations before conducting maintenance on the switch power supply. Firstly, it needs to be visually inspected, and in special or necessary situations, a magnifying glass should be used to carefully observe it. For sniffing work, it also has its important significance. For experienced maintenance personnel, they can determine the location of burnt components based on the smell. And it can accurately determine the faults of some seemingly intact components.
The first step is to check the power supply. At this time, we not only need to use a multimeter to detect its voltage value, but also need to use an oscilloscope to detect its voltage waveform.
The second step is to check the crystal oscillator. In this step, we need to see if the crystal oscillator is starting to vibrate. We need to use an oscilloscope to detect the waveform of its crystal oscillator foot.
The third step is to check the reset status. We can check whether the reset signal is normal or not, and determine 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. If any of these buses encounters a problem, it will cause a malfunction. In such cases, we can use the method of detecting the resistance of parallel buses to ground to check if a fault has occurred in a certain circuit. Of course, we can also make a judgment by observing the waveform of each bus.
The fifth step is to check the interface chip, as the damage rate of this device is the highest. We can use substitution or even specialized instrument detection to determine the fault.
The sixth step is the replacement of components. After conducting the above inspection, we will find that a certain component has malfunctioned, and at this time, we need to take action to address the issue. The methods of handling include repairing circuits, replacing components, and renovating.
The seventh step is to test the power supply. After troubleshooting, we must conduct offline loading tests before starting the machine. Only after normal testing can the machine load be tested and used.
