home > News > Industry News

Troubleshooting method of switching power supply,CE ADAPTOR wholesale

source:Industry News     Popular:adapter     release time:2022-04-25 11:37:50     Article author:yu    

  Troubleshooting method of switching power supply,CE ADAPTOR wholesale(图1)

  1. In the case of power failure, "look, smell, ask, and cut"

  First of all, before the switching power supply is not powered on, use a multimeter to measure the voltage across the high-voltage capacitor. If the fault is caused by the failure of the switching power supply or the open circuit of the switching tube, in most cases, the voltage across the high-voltage filter capacitor has not been discharged, and this voltage is more than 300 volts. You leave unforgettable memories!

  Since the maintenance power supply needs to be exposed to 220V high-voltage electricity, once the human body touches the voltage above 36V, it will be life-threatening. Therefore, under possible conditions, try to check whether there is any obvious short circuit or component damage in the power-off state. First, open the shell of the power supply, check whether the fuse is blown, and then observe the internal situation of the power supply. If you find that the components on the PCB board of the power supply are broken, you should focus on checking this component. Generally speaking, this is the main reason for the failure; smell the power supply Check if there is a smell of paste inside, check if there are burnt components; ask about the damage to the power supply and whether there is any illegal operation on the power supply, which is necessary for repairing any equipment. After the initial inspection, a more in-depth inspection of the power supply is required.

  Use a multimeter to measure the forward and reverse resistance at both ends of the AC power cord and the charging condition of the capacitor. If the resistance value is too low, it means that there is a short circuit inside the power supply. Under normal conditions, the resistance value should reach more than 100 kiloohms; the capacitor should be able to charge and discharge, if damaged , it is shown that the resistance at both ends of the AC power line is low and is in a short-circuit state, otherwise the switch tube may be broken down. Then check that the DC output part is disconnected from the load, and measure the resistance to ground of each group of output terminals. When it is normal, the needle should have a capacitor charge and discharge swing, and the last indication should be the resistance value of the bleeder resistor of this circuit. Otherwise, most of them are caused by reverse breakdown of the rectifier diode.

  2. Power-on detection

  After passing the above tests, the power-on test can be performed. At this time is the key, need to have certain experience, electronic foundation and maintenance skills. Generally speaking, you should focus on checking the input end of the power supply, the switching transistor, the power supply protection circuit, and the output voltage and current of the power supply. If the power supply starts and then stops, the power supply is in the protection state, and the voltage of the protection input pin of the PWM chip can be directly measured. If the voltage exceeds the specified value, it means that the power supply is in the protection state, and the reason for the protection should be checked. Due to exposure to high voltage, it is recommended that friends without electronic foundation need to operate carefully.

  3. Common faults

  3.1. Fuse blown

  Generally, a blown fuse indicates a problem with the internal wiring of the power supply. Since the power supply works under the condition of high voltage and high current, the fluctuation and surge of the grid voltage will cause the current in the power supply to increase instantaneously and cause the fuse to blow. The key point should be to check the rectifier diodes, high-voltage filter electrolytic capacitors, inverter power switch tubes, etc. at the power input end, and check whether these components have breakdown, open circuit, damage, etc. If the fuse is indeed blown, you should first check the various components on the circuit board to see if the surface of these components is burnt and whether there is electrolyte overflow. If the above situation is not found, use a multimeter to measure whether the switch tube has a breakdown short circuit.

  3.2. No DC voltage output or unstable voltage output

  If the fuse is intact, there is no output of DC voltage at all levels under load conditions. This situation is mainly caused by the following reasons: open circuit and short circuit in the power supply, failure of the overvoltage and overcurrent protection circuits, the oscillation circuit does not work, the power supply is overloaded, and the rectifier diode in the high frequency rectifier filter circuit is broken down. Filter capacitor leakage, etc. After measuring the secondary components with a multimeter, after ruling out the breakdown of the high-frequency rectifier diode and the short-circuit of the load, if the output is zero at this time, it is certain that the control circuit of the power supply is faulty.

  3.3. Poor power load capacity

  Poor load capacity of the power supply is a common fault, which usually occurs in old-fashioned or long-working power supplies. Should focus on checking whether the Zener diode generates heat and leakage, the rectifier diode is damaged, the high-voltage filter capacitor is damaged, etc.


Read recommendations:

MKS-120200EU-36 Switching Power Supply

60W 6USB Charger,60W Charger,6USB Charger,Charger

ER42 High Frequency Transformer

Mechanical performance test of plug power cord

How to design an excellent battery charger adapter.power adapter Factory

Related Information

What are the conditions of use and maintenance methods for switching power supplies?

2022-05-21

Some Frequently Asked Questions about Power Adapters

2022-05-20

How to deal with the electromagnetic interference of switching power supply which is difficult in EM

2022-05-19

Six situations and solutions that cause the whistling of switching power supplies.power supply price

2022-05-18

Lightning Surge Test Method for Switching Power Adapters.adapter factory

2022-05-17

Two common power adapter output overload protection methods.ADAPTOR price

2022-05-16

Common fault maintenance skills of switching power supply

2022-05-14

How should we choose the charger?

2022-05-13

Power adapter expertise.CE ADAPTOR

2022-05-12

How to solve the high temperature rise of switching power supply transformer?

2022-05-11

The role of varistor in switching power supply

2022-05-10

Structural characteristics and working principle of varistor

2022-05-09

The role of varistor in switching power supply

2022-05-09

What are the main components of switching power supply

2022-05-07

Two ways for MOS devices to dissipate in high-power power supplies,CE ADAPTOR Processing

2022-05-06

Several common insulation protection technologies for power adapters

2022-05-05

What are the unique advantages of high frequency switching power adapter

2022-04-27

What are the main components of switching power supply.China cnc plastic cutting

2022-04-26

Troubleshooting method of switching power supply,CE ADAPTOR wholesale

2022-04-25

How to use the power adapter correctly

2022-04-23

What is the comparison between a charger and an adapter?

2022-04-23

The optimal solution of drone power management solution!

2022-04-22

Several common insulation protection technologies for power adapters

2022-04-21

What are the unique advantages of high frequency switching power adapter

2022-04-20

General Mechanism Analysis of Switching Power Adapter.ac power adapter wholesaler

2022-04-19

Suppression method of low frequency ripple of switching power supply

2022-04-16

Why is the power adapter making noise?

2022-04-15

When the power adapter is in normal use, what is the normal temperature?

2022-04-14

90% of people use the car charger incorrectly, are you using it right?CAR POWER SUPPLY sales

2022-04-13

The difference between a power adapter and a voltage regulator

2022-04-12

Popular recommended products

MKS-120200BS-36 Switching Power Supply

2020-08-29

45W PD Charger,45W Charger,PD Charger

2020-08-27

Transformer,High Frequency Transformer,Frequency Transformer

2020-08-27

EI-57 ADAPTER LINEAR ADAPTOR Linear Power Adapter Switching Power Adapter INTERCHANGEABLE ADAPTOR Li

2020-08-28

MKA-571652420 ADAPTER AC ADAPTER CE ADAPTOR UL ADAPTOR Linear Adapter

2020-08-28

10-24W Charger,24W Charger,10W Charger

2020-08-27

30-500W LED Power Supply 30-500W Power Supply

2020-08-27

60W 6USB Charger,60W Charger,6USB Charger,Charger

2020-08-27

12W CAR CHARGER,12W USB CAR CHARGER,CAR CHARGER,12W CHARGER

2020-08-27

MKS-120200EU-36 Switching Power Supply

2020-08-29

QC3.0 24W USB Charger,24W USB Charger,24W USB Charger,USB Charger

2020-08-27

MKS-1202000-36 Switching Power Supply

2020-08-29

36-65W Switching Power Supply

2020-08-29

MKS-1203000EX Switching Power Supply

2020-08-29

24-65W Medical Switching Power Supply

2020-08-27

24V21A LED Power Supply 24V Power Supply 21A Power Supply

2020-08-27

12W POWER SUPPLY,12W CAR POWER SUPPLY,POWER SUPPLY,CAR POWER SUPPLY

2020-08-27

3-12W Medical Switching Power Supply 3W Switching Power Supply 12W Power Supply

2020-08-27

24-65W Switching Power Supply

2020-08-29

EI-66 ADAPTER LINEAR ADAPTOR SWITCHING ADAPTOR Linear Power Adapter Linear Adapter

2020-08-28

12-36W POE POWER SUPPLY

2020-08-27

3-100W PCBA power supply 3-100W Customized power supply 3-100W power supply

2020-08-27

3-15W Switching Power Supply

2020-08-28

Transformer,Power Transformer,Ring Power Transformer

2020-08-27

EI-35 ADAPTER AC ADAPTER SWITCHING ADAPTOR Linear Power Adapter Linear Adapter

2020-08-28

200-500W Switching Power Supply

2020-08-29

EI-48 ADAPTER LINEAR ADAPTOR Switching Power Adapter INTERCHANGEABLE ADAPTOR Linear Adapter

2020-08-28

18-25W Switching Power Supply

2020-08-28

ER42 High Frequency Transformer

2020-08-27

12W 2USB Charger,2USB Charger,12W Charger,USB Charger

2020-08-27
Copyright 2020 © Merryking Technology Co., Ltd. All rights reserved