A: Model: IPE300-090G-4

Application condition: Ordinary speed regulation of washing machine. 

Fault phenomenon: After the VFD is powered on, the display screen flashes once and then goes out, repeating the cycle. 

How to solve it?

Reason analysis: 

The static measurement main circuit is intact. Measure that there is no 10V or 24V voltage at the motherboard terminals when powered on. Disassemble and inspect the U-phase circuit of the drive board. There is a voltage regulator tube that has changed color. Check for abnormal IGBT junction capacitance corresponding to phase U. Analysis shows that the short circuit at the IGBT trigger end resulted in the protection of the switch power supply on the drive board. 

Solution:

 Replace with a new driver board and U-phase IGBT. 

Improvement effect: 

The motherboard displays normally and the motor runs normally.