Since the car inverter circuit is generally equipped with the soft start function, the output of the ac 220V will not be communicated until after the power supply is switched on, and the LED indicator light will be lit. When the LED indicator is not on, the inverter circuit does not work.
More than 30 s when switching power supply, the LED indicator light is not lit, you will need to measure XAC output socket of the ac voltage value, if the voltage is normal about 220 v, the specification is only the LED light is part of the circuit fails; If the ac voltage value of the XAC output socket is 0, the failure reason is that the inverter before the inverter is not working. It may be that the protection circuit inside the chip IC1 has been started.
Whether internal protection circuit chip IC1 start-up method is: use the multimeter dc voltage in measuring chip IC1 3 feet of dc voltage value, if the voltage is explained in more than 1 v is chip has launched the internal protection circuit, or explain the cause of the problem is a protection circuit action.
If chip IC1 3 feet of voltage value above 1 v, suggests that chip internal protection circuit has started, need further with multimeter dc voltage test chip IC1 dc voltage between 15 and 16 feet, as well as the chip IC1 dc voltage between 1 and 2 feet. Under normal circumstances, in the circuit chip IC1 15 feet of dc voltage should be higher than 16 feet of dc voltage, 2 feet of the dc voltage of the dc voltage should be higher than 1 foot, only when these two conditions are satisfied at the same time, the chip IC1 3 feet of dc voltage can be normal about 0 v, inverter circuit to work properly. If a test voltage is found not to satisfy the above relationship, the problem can be solved by simply finding the cause of the fault by the corresponding branch.