Laptop charger housing disassembly method

Analysis of charger housing structure

Next, let’s take a look at the internal structure of the laptop charger housing. The main components of the circuit have been marked with a circle, the part name and function are as follows:

1. A varistor whose function is that when the external voltage is too high, the resistance of the varistor quickly becomes very small, and the fuse connected in series with the varistor is blown, thereby protecting other circuits from being burned out.

2. The fuse has a specification of 2.5A/250V. When the current in the circuit is too large, the fuse will blow to protect other components.

3. Inductor coil, the main function is to reduce electromagnetic interference.

4. Rectifier bridge, the specification is D3SB, the function is to convert 220V AC into DC power.

5. Filter capacitor, the specification is 180μF/400V, the function is to filter the AC ripple in DC, which makes the circuit work safer.

6. An important part of integrated circuits, protection circuits, and voltage regulation.

7. The temperature probe is used to detect the internal temperature of the charger case. When the temperature is higher than a certain set value (the charger case of different brands has a slightly different temperature value), the protection adapter is not damaged.

8. High-power switch tube is one of the core components in the switching power supply.

9. Switching transformer, one of the core components in the switching power supply.

10. Secondary rectifier, the function is to change the low-voltage alternating current into low-voltage direct current. In IBM’s charger housing, the rectifiers are often operated in parallel with two high powers to achieve a large current output.

11. Secondary filter capacitor, 820μF/25V, has two functions to filter the ripple in low voltage DC. In addition to the above components, there are adjustable potentiometers and other RC components on the board.

Disassembly of the charger housing

The upper and lower covers of the laptop charger case are either injection molded or glued with super glue, without any screws. However, as long as the method is correct, the disassembled charger casing can be completely restored to its original state, and it is almost impossible to observe the traces of the disassembled.

Disassembly tools: electrician knife, hammer, screwdriver, electric iron, utility knife, etc.

Place the lateral side of the charger casing on the white paper, cut it through the gap between the upper and lower covers of the charger casing with an electric knife blade, and then tap the back of the electrician knife with a hammer to cut the electrician knife between the upper and lower covers of the adapter. At different positions of the gap between the upper and lower covers of the adapter, use the tip of the electrician knife to move along the slit. When a certain part of the upper and lower covers is first cracked, the tip of the blade is deepened, and then the upper and lower covers of the adapter are slowly separated.

In order to open the charger case of the outer casing, you can see that the adapter circuit has a copper shield on the outside of the adapter circuit, use a utility knife to cut the tape on the shield, and then solder the shield to the inner circuit board.