1, check the power supply (the power supply is the source of the whole machine power, and the latter can only be guaranteed after the power supply is correct)
2. Detecting oscillation part (waveform generation), waveform shaping circuit, driving stage and power (current) output circuit.
Note: The oscilloscope can see the waveforms (shape, voltage amplitude, etc.) in various places, and the double-integral oscilloscope can see the phase angle between the output waveforms of the frequency converter, for example, the angle between two phases of a three-phase frequency converter must be 120). If there is no oscilloscope, use a multimeter to test the AC gear (pay attention to the gear to avoid burning the instrument).
3. Tell the details first. After locking the fault range, it is necessary to measure the components in a certain area, such as triode, resistance-capacitance period and so on. These are the basic things (you can leave me a message if you don't understand the specific period).
4. When conditions are limited, traditional diagnostic methods should be adopted: looking, smelling, asking and touching.
Look: Look for periodic burning, discoloration and deformation (capacitance bulging, leakage, black resistance ...)
Smell: Turn on the machine for a short time and smell if there is any smell inside the machine.
Q: Ask the maintenance personnel about the characteristics of equipment failure (what happened before and after the failure, qualitative soft failure, permanent failure).
Touch: Touch whether the relevant equipment is in working state (the working state of the equipment can be judged by the temperature: without temperature, it may not work; The temperature is too high or too hot, indicating that the equipment or surrounding circuits are faulty)