Repair method of electric scooter charger failure

Article from: 03-09-2020


1. When charging, the power indicator is on and the charging indicator is orange

First, please check whether the charger output plug and the charging plug of the battery box are inserted tightly. If you are sure that there is no problem, check whether the fuse tube on the battery box is open or the fuse holder is loose and bad. In addition, some models can only be charged after opening the battery lock. If all the above faults are eliminated, consider whether the output line of the charger is open. Use a multimeter voltage block (200V block) to measure the no-load output voltage of the charger. It should be 41-44V (with 36V battery, different chargers are different) If not, the output line of the charger may be open, turn on the charger and change the output line to eliminate the fault. Note: When replacing the output cable of the charger, be sure to not reverse the polarity of the original device.

2. The power indicator light is off, and the charging indicator light is off

Check whether the charger input power plug is properly connected to the mains. You can plug the charger input plug into a normal power socket and try it. If the situation persists, open the charger shell and observe whether the fuse in the machine is broken, such as If it is not broken, first check whether the power input line is in good condition. After troubleshooting the power input line, check whether the components near the high-voltage area on the circuit board have false soldering and whether the fuse holder has bad contact. Check the transformer T1. , Whether there is a virtual welding phenomenon in the transistors V1, V2, etc. In addition, R5 or R6 open circuit will also cause the above faults. If the fuse inside the machine is broken, never replace the large ampere fuse tube (the fuse tube of the charger is generally 2A). Check D1-D4, V1, and V1. Whether V2, R4, R7, D15, D21 are damaged, if damaged, they can be replaced with the same type. Please note that when the above-mentioned components are damaged, one or two of them may be damaged at the same time, and sometimes several of them may be damaged at the same time. During maintenance, you need to check and replace these components one by one before powering on.

3. Severe heat, and even the shell is burnt and deformed

This is mainly because some users often carry them with the scooter, causing some components to loosen. The main performance is: when C18 is loose and soldered, it will cause abnormal working conditions of V1 and V2, and the heat is very large. In severe cases, the charger shell is deformed and the circuit board is burnt, causing V1 and V2 to be damaged. C18 can be re-soldered and checked. V1, V2, R4, R7. If the fault still cannot be eliminated, check whether there is an open circuit in D15 and D21. In addition, some manufacturers use a double diode in the output rectifier tube. An open circuit can also cause the above-mentioned fault. Sometimes the fault will cause V1, V2 One is damaged. Need to be checked and replaced at the same time.

Fourth, the heat is large and accompanied by abnormal noise

The cause of the fault is the damage of the output stage damping resistors R31 and C17. In addition, C12 open circuit or virtual welding can also cause the above failures.

5. There are abnormal noises during work and cannot be charged

Check whether C8 on the circuit board is soldered or damaged. Generally, replacing C8 can solve it.

6. There is abnormal noise during work, and the power indicator and charging indicator are dark and flashing

The cause of the failure is that IC1 is damaged. Be careful when replacing it. Do not damage the copper foil of the printed board. After the replacement is normal, you need to adjust R28 to make the charger output voltage within the normal operating range.

Seven, the output voltage is very high

The output voltage is very high (greater than 50V), and the cause of the fault is C15 short circuit or R26 open circuit. The voltage on pin "1" of IC1 integrated circuit can be measured for specific judgment.

Note: After replacing R26, R28 should be readjusted to keep the charger output voltage normal.

8. The output voltage is normal, but the charging current is small

Check whether R30, R11, R13 are in poor contact or damaged. If normal, replace IC1 to eliminate the fault.

Nine, the output voltage is normal, the charging indicator has no indication or the indication is incorrect

Usually because IC2 is damaged or LED2 is damaged, it can be replaced.

Ten, the output part of the copper foil is blown

After turning on the charger, it is found that the copper foil of the output part of the charger is broken. This is usually the result of reversely connecting the positive and negative electrodes of the battery. The resulting failure will cause damage to many components of the charger. If the charger fuse is not broken, usually replace the R30, IC1, IC2 and connect the broken copper foil to return to normal. If the fuse of the charger is broken, the serious fault D1-D4, V1-V2, R4, R7, etc. may be damaged, and they need to be replaced one by one after measurement.

Common faults of electric scooter chargers

1. The power supply does not start: plug in the power supply, the large capacitor has a voltage of 300V, unplug the power supply and re-measure whether the 300V voltage at the second end of the large capacitor does not drop. After discharging the capacitor, replace the starting resistor. The starting resistance is in the power input part, the resistance is 150K, and the power is 2W.

2. The power supply does not start: plug in, the large capacitor has a voltage of 300V at 2 terminals, unplug the power supply, the large capacitor voltage slowly drops, check all the circuit boards for de-soldering phenomenon, after the repair welding is completed, replace the 3842 with a new one Yes, just power on and test the machine.

3. Flashing light: first repair the circuit board and try the machine again. If it still flashes, please check the output terminal sampling resistance. 0.1 Euro. 3W power. Connect it to the negative end of the output line and replace this resistor with a new one.

4. The output voltage is high, power on, the voltage is higher than 70V, charging does not turn the light, first repair the circuit board, and try again, if the voltage is still high, please replace the photocoupler, try again, or the output is high , Replace the 431 reference regulator, and test the machine again.

5. Squeaking, heating, insufficient charging: power on and measure the voltage of the large capacitor, as long as it is lower than 300V, the general capacitor will fail and you can replace it.

6. If fever is severe, please replace the fan with a new one.

7. The output voltage is unstable. First repair the circuit board, then test the machine, and then replace the output capacitor 63V470UF with a new one.

8. If charging does not turn on the light, use the tester to test the data, and then replace the 358 or 324 with a new one.

9. The charging is unstable, sometimes it can be charged, sometimes it can't be charged. Use the tester to check the data, and then replace all the input and output power cords with new ones, repair the circuit board and test the machine.

10. Power on and burn insurance: first check whether the power tube is broken down, if not, replace all 4 rectifier diodes with new ones, and test the machine.

11. There is no output when power is on, power on and test the machine. There is a 300V voltage at the 2 end of the large capacitor and it slowly drops. First, check whether the large diode at the output end has broken down, repair the welding, and try the machine again.

12. Turn on 2 red lights when power on: power on and test the machine, whether the no-load voltage is normal, then replace 358 or 324 with a new one.

13. There is no output when power is on, it can start normally, and the indicator is normal. First, replace the output line with a new one. For the charger with a relay, directly short-circuit the relay for test.

14. Power on the flashing light, please repair the pins of the transformer, and then test the machine. If it still remains, please check whether the 431, photocoupler, output diodes are short-circuited, whether the transformer core is loose, and whether the 10 ohm resistance of the power input section open circuit. Or substitute 3842 to try the machine again.

15. When charging does not turn the lights, first use a tester to check the data. Generally, the voltage of a new battery is not higher than 59.5, and the battery is not higher than 58.8 after charging for half a year.

16. Low output voltage: repair welding circuit boards. Test the machine, and then replace the large input and output capacitors with a new one.

17. The output is low and hot. If the output voltage is lower than 40V and the power tube and transformer are hot, it is generally a problem with the transformer.

18. Startup is difficult, sometimes it can work and sometimes it can't be started, repair the circuit board, and then test the machine. If you still need to change the input part of the small capacitor, try again, 50V47UF.

19. After burning the 3842, 3842, plug in the test machine and hear a click. This is the measurement of the large capacitor 2 terminal voltage 300V slowly, indicating that 3842 has broken down again, first repair the circuit board, check the transformer lead Whether the pin is loose or the lead wire is disconnected, whether the large diode of the output part is open, whether the circuit board is broken.

20. The above faults are suitable for most common faults of single-tube circuit chargers on the market. Consultation is available at any time during operation