Often, the inverter has only one fault, but it is very important for the repairman to find the fault point, deal with the problem in a targeted manner, minimize useless disassembly, and especially minimize the use of soldering irons. In addition to experience, it is also very necessary to master the correct inspection method. The correct method can help maintenance personnel quickly narrow the detection scope from outside to inside, from complex to simple, find out the fault and properly handle it for repair.

1. Alarm parameter inspection method: The inverter will give corresponding error information for voltage, current, temperature, communication and other faults. The inverter, which mostly uses a microprocessor or DSP processor, will have special parameters to save alarm records for more than 3 times.

2. Analogy inspection method: This method can be an analogy of the same circuit itself, or an analogy of a faulty board and a known good board. This can help repairmen quickly narrow the scope of inspection.

3. Replacement inspection method for spare boards: Using spare circuit boards or circuit boards of the same type to confirm the fault and narrow the scope of inspection is an effective method.

4. Isolation and inspection method: It is usually difficult to determine in which area certain faults occur. The isolation method can simplify complex problems and quickly find the cause of the fault.

5. Visual inspection method: It uses the sensory organs of human hands, eyes, ears, and nose to find the cause of the failure.

6. Rising cooling inspection method: This method is very effective for some special faults. Artificially heat or cool some components with poor temperature characteristics to produce "symptoms" or eliminate "symptoms" to find the cause of the fault.

7. Destruction inspection method: refers to taking some measures to cancel internal protection measures, simulate fault conditions, and destroy the problematic devices. Make the faulty equipment or area stand out.

8. Knocking inspection method: Use an insulating rubber stick to knock on the suspected defective part. If the inverter fault disappears or reappears, it is likely that the problem lies there.

9. Scrubbing inspection method: Many special faults are sometimes absent and looming, and cannot be judged and handled. At this time, you can use clean water or alcohol to clean the circuit board, and use a soft brush to brush off the dust and rust on the circuit board. Pay special attention to places where solder joints are dense, clean the vias and circuits close to the 0-volt copper layer, and then blow dry with hot air. Often unexpected results are achieved. At least it helps the application of observation methods.

10. Principle analysis inspection method: Principle analysis is a very fundamental method for troubleshooting. If other inspection methods are ineffective, you can start from the basic principles of the circuit and check step by step to find out the cause of the fault.