1. Power does not start: plug in the power supply, the large capacitor has a voltage of 300V, pull out the power supply and measure again whether the voltage of the two terminals of the large capacitor does not drop. After discharging the capacitor, replace the starting resistance. The starting resistance is in the power input part, the resistance value is 150k, and the power is 2W.

2. Difficult to start: sometimes it can work, sometimes it can't be started. Repair the circuit board, and then test the machine. If it still works, please replace the input part of the small capacitance and try the machine again, 50v47uf.

3. Electric car charger always green: there are four cases. If the converter of the charger is damaged and cannot be converted and charged, replace the charger resistor; if the battery is open and checked with a multimeter; if the charger fuse is burnt out, replace the charger; if the power cord and battery socket fall off and have poor contact, check and replace it.

4. Electric car charger always red light: This is the battery polarization and battery water loss. It can be restored by timely maintenance. The method is as follows: add 15ml pure water to the battery, charge it with 4 a current until the current drops to 1 A, park for 2 hours, and measure the voltage of each battery is 13.3. If one of the batteries fails to reach the required value, charge the battery until it reaches the limit. Then string the batteries together and it's OK.

5. High output voltage: power on, the voltage is higher than 70 V, charging does not turn the lamp, first repair the circuit board, and then try the machine again. If the voltage is still high, please replace the optocoupler, try the machine again, or the output is high, replace 431 reference voltage regulator and try the machine again.

6. High heat and abnormal noise: the fault is caused by the damage of the damping capacity R31 and C17 of the output stage. In addition, open circuit or false soldering of C12 can also cause the above faults.

7. Unstable output voltage: first repair the circuit board, then test the machine, and then replace the output capacitor 63v470uf with a new one.

8. Charging does not turn the lamp: use the detector to test the data, and then replace the 358 or 324 with a new test machine.

9. The output voltage is normal, but the charging current is very small: check whether R30, R11 and R13 are in poor contact or damaged. If it is normal, please replace IC1 to eliminate the fault.

10. Power on and burn the fuse: first check whether the power tube is broken down. If not, replace all four rectifier diodes and test the machine.

11. Power on without output: power on and test the machine, and the voltage at the two ends of the large capacitor is 300V, and it decreases slowly. First, check whether the large diode at the output end is broken down, repair welding, and try the machine again.

12. Turn on two red lights when power on: power on the machine, check whether the no-load voltage is normal, and then replace 358 or 324 with a new one.

13. Power on without output: it can start normally and the indicator light is normal. First, replace the output line. For the charger with relay, the relay will be tested.

14. Power on flash lamp: please repair the pins of the transformer, and then test the machine. If it is still the same, please check whether the diodes of 431, optocoupler and output part are short circuited, whether the magnetic core of transformer is loose, and whether the 10 ohm small resistance of the power input part is open circuit. Or replace 3842 to test the machine again.

15. Do not turn the lamp: first use the tester to test the data. Generally, the voltage of the new battery is not higher than 59.5, and it is not higher than 58.8 after half a year of charging. If the voltage is higher than this, the lamp may not be turned.

16. Low output voltage: repair welding circuit board. Test the machine, and then replace the input and output large capacitance to test again.

17. Low output, hot: if the output voltage is less than 40 V, and the power tube, transformer is hot, generally for the transformer has problems.

18. Squeaking, heating, insufficient charging: power on to measure the voltage of the large capacitor, as long as it is lower than 300V, the general capacitor is invalid and can be replaced.