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How to check if the power supply fails?

How to check if the power supply fails?
Update Time:2019-05-14

Many people have some problems soon after they bought the power adapter. Are these really "problematic"? The following is a common sense of the charger manufacturer, and the "problem" will be solved after understanding.


Many people have some problems soon after they bought the power adapter. Are these really "problematic"? The following is a common sense of the charger manufacturer, and the "problem" will be solved after understanding.

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

First check that the charger output plug and battery compartment charging plug are not plugged in. If there is no problem, check if the fuse on the battery compartment is open or in contact with the fuse holder. In addition, some models require a battery lock To be turned on before charging. If all the above faults are eliminated, please consider whether the charger output line is turned on, and use the multimeter voltage stop (200V shift) to measure the no-load output voltage of the power supply unit. The voltage should be 41-44v (36V battery is different depending on the charger) And different), if not, it may be that the charger output line is turned on, and the charger is turned on, and the output line is replaced to Note that the charger output line, it must be noted that the positive and negative poles of the original machine are not connected.


2. The power indicator does not turn on and the charging indicator does not light.

Check if the power adapter input power plug is well connected to the power supply. Try plugging the charger input plug into a normal power outlet. If the condition persists, open the charger case and observe if the fuse in the machine is broken. Check that the input line is good. After troubleshooting the input line, check the components near the high voltage area of ​​the board for virtual soldering and the fuse holder for poor contact. It is mainly discussed whether there is a virtual soldering phenomenon In addition transformer T1 and the transistors V1 and V2. In addition, if R5 or R6 is turned on, it will also cause a malfunction. If the internal fuse is broken, do not replace the large amp fuse (usually a 2A charger). The attention should be on D1-D4, V1, V2, R4, R7, D15, D21. If damaged, the same type can be replaced. Please note that when the above components are damaged, one or two may be damaged at the same Time, and sometimes several may be damaged at the same time. Durin g the overhaul, they need to be inspected and replaced one at a time before they can be powered.


3. Severe fever, even the burning deformation of the outer casing.

The main findings are as follows: When C18 is loose and virtual welding, it will cause abnormal working state of V1/V2. In severe cases, it will cause thermal Deformation of V1/V2 and burnt of the board, resulting in damage of V1/V2, thus making V1 Re-weld /V2/R4/R7 and check V1/V2/R4/R7. If the fault cannot be eliminated, please check If there is an open circuit in D15N and D21. In addition, some manufacturers use dual diodes as output rectification, one of which can also cause a fault, sometimes resulting in V1, one of which is damaged. Need to check and replace at the Same time.


Large heat generation with abnormal noise

The fault is caused by the failure of the output stage damping resistors R31 and C17. In addition, C12 open circuit or virtual soldering can also cause the above faults.


5. There is abnormal noise during work and it cannot be charged.

Check if there is any solder joint or damage on C8 on the circuit board. Generally, replacing C8 can solve it.


6. There is abnormal noise during operation, and the power indicator and charging indicator are blinking.

The fault is caused by the damage of IC1. Be careful when replacing it. Do not damage the copper foil of the printed board. Replace it properly. You need to adjust the output voltage of the R28 power adapter within the normal working range.

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