Inspection and repair of loose solder joints inside the charger

Loose solder joints inside the charger can affect its normal operation. The following are the relevant methods for inspection and repair:

Inspection method

Visual inspection:

Open the charger casing and carefully check whether there are any false solders or component desoldering at each solder joint on the circuit board, especially for large-mass components such as high-frequency transformers, high-voltage filter capacitors, and inductors.

Power-on test

Under the condition of ensuring safety, conduct a power-on test on the charger to observe whether it can work normally and whether the indicator light status is normal. If any abnormality occurs, such as the indicator light not lighting up or unstable charging, it may be caused by loose solder joints.

Multimeter testing

Use a multimeter to measure the voltage and resistance at key points on the circuit board to determine if there is an open circuit or poor contact. For instance, measure whether there is a 220V input in the power supply line and whether there is a DC voltage close to 300V on the high-voltage filter capacitor, etc.

Repair method

Re-welding

For the found false or de-soldered solder joints, re-solder them using an electric soldering iron and solder. Before soldering, make sure the soldering iron is preheated thoroughly and the soldering point is clean and free of impurities. When welding, it is necessary to control the time and temperature well to avoid damaging the components.

Reinforcing components:

For some components that are prone to loosening, such as large capacitors and inductors, glue or fixed brackets can be used for reinforcement to prevent the solder joints from loosening due to shaking during use.

Replace the damaged components:

If any components such as resistors, capacitors, diodes, etc. are found to be damaged during the inspection process, new components need to be replaced in a timely manner. When replacing components, pay attention to their specifications and parameters to ensure they are consistent with the original components.

Precautions

Safety first

Before conducting inspections and repairs, make sure the charger is powered off to avoid the risk of electric shock. At the same time, it is necessary to prepare appropriate tools, such as screwdrivers, tweezers, soldering irons, etc., and ensure that the tools are in good condition.

Recording and Marking:

When disassembling the charger's casing and circuit board, pay attention to the position and connection method of each component, make records and marks, so that it can be correctly reassembled after repair.

Professional maintenance

If you are not familiar with the internal structure and circuit of the charger or cannot determine the cause of the fault, it is recommended not to repair it blindly by yourself to avoid causing greater damage or safety hazards. At this point, the charger should be sent to a professional repair shop for maintenance.