Owners of Xiaomi equipment often face the need to open the charger when the adapter stops working or begins to make extraneous sounds. Disassembly of the power supply may be required to replace the burned fuse, check the capacitors or clean the contacts after moisture. However, it is worth remembering that there are elements inside under high voltage, which requires extreme caution.
Modern Mi Charger adapters are designed to be monolithic, making them difficult to dismantle without damaging the body. Manufacturers use ultrasonic plastic welding to ensure the device is tight and safe. Despite this, accurate repair is possible with the right tools and understanding of the design of electronic components.
Before you start to physically affect the housing, you need to evaluate the feasibility of intervention. If the device is under warranty, any violation of the seals will lead to a denial of service. In other cases, when the power supply is out of order and cannot be replaced, disassembly becomes the only way to bring it back to life or dispose of components.
Necessary tools and measures of prejudice
To do the job properly, you will need a specific set of tools that are not found in every home, the main obstacle is the durable plastic of the case, connected without visible screws, you will need a thin metal scalpel or a special knife to open the electronics, and a flat screwdriver.
Safety is the number one priority for any electrical appliance, and even after disconnecting from the power supply, there may be residues of charge on the capacitors, and high voltage is life-threatening, so you can't touch the board with your bare hands immediately after you've been removed from the power outlet.
⚠️ Warning: Before starting work, make sure the charger is completely disconnected from the power grid at least 30 minutes ago.
It is also recommended that tweezers be prepared to extract small parts and a magnifier to inspect the chips. If soldering is planned, a soldering iron with a thin sting and solder will be required.
- 🔧 Thin knife or scalpel to cut the seam.
- 🪛 Small sized flat screwdriver for plastic deflection.
- 🔍 Loop or magnifying glass for inspection of board.
- 🔌 Multimeter to check the integrity of contacts.
☑️ Preparation of the workplace
Features of the design of adapters Xiaomi
Xiaomi engineers are focusing on the compactness of their devices, which directly affects the density of the interiors. Inside the plastic case, there is a printed circuit board that houses the transformer, charge controller and rectifying diodes, all of which are compounded or tightly pressed together to minimize vibrations.
The charger body typically consists of two symmetrical halves connected around the perimeter. Some models, such as the Mi Fast Charger, use an additional internal frame to hold the board, which complicates the process of accessing the electronics, since after opening the outer seam, you need to gently flick the internal locks.
Why is the body sealed?
An important feature is the presence of heat-resistant plastic, which is difficult to mechanically affect. When you try to force open, there is a risk of splitting the body, which will make subsequent assembly impossible without the use of glue. Ultrasonic welding creates a monolithic seam that is almost impossible to separate without damaging the structure of the material.
Step-by-step instructions for opening the body
The disassembly process begins with finding the seam connecting the two halves of the body. Carefully inspect the perimeter of the Xiaomi charger. Take a thin knife and at a 45-degree angle, begin gently inserting the blade into the joint. The movements should be forward, not stabbing, so as not to damage the internal board.
Walk the knife around the perimeter, gradually going inwards. When the blade has entered sufficient depth, you can use the flat screwdriver as a lever. Put it in a place where the seam is already a little apart, and in a careful turn try to push the halves apart. Audible click will indicate that one of the internal locks is released.
⚠️ Attention: Don't put too much effort. If the case doesn't lend itself, you probably haven't cut through the weld to the end, and there's a risk of breaking the plastic latches.
When you remove the lid, you'll have access to electronics, and the board can be mounted on screws or simply inserted into the slots, and if you see screws under the cross screwdriver, unscrew them, and some models have adhesive-based board, and you'll need to tweak the edges carefully.
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Warming up the body with a hair dryer for 1-2 minutes can soften the glue and plastic, which will make it easier to open, but do not overheat the device so as not to damage the components.
- 🔪 Insert the knife in the seam around the circle of the device.
- 🔄 Turn the knife carefully, deepening the incision.
- 🪛 Use a screwdriver to snap the locks.
- 👐 Remove the lid by pulling it to the side.
Diagnostics and troubleshooting
Once the board is successfully removed, you need to do a visual inspection of the components. Most often, the cause of failure of Xiaomi chargers is capacitor bloating or blackening of the elements due to overheating. Notice the condition of the fuse, which often burns out when voltage surges in the network.
If you can't see any external damage, you'll need to vertebrate the circuits with a multimeter, check the input voltage on the contacts where the plug is inserted, and the output on the fork. USB-The lack of resistance in certain areas will indicate a cliff or short circuit, and diagnostics require knowledge of electronics, because misinterpretation of readings can lead to faulty repairs.
Pay special attention to the area around the transformer and the diode bridge, which is where the most heat is generated, often the soldering of contacts due to heating and cooling cycles cracks, reconnecting with soldering can solve the problem of unstable operation.
| Component | Sign of malfunction | Probable cause | Repair method |
|---|---|---|---|
| Capacitor | Bloating lid, leaking. | Overheating, surge of tension | Replacement by similar |
| Safety lock | Blackening, breaking the thread | Short circuit. | Replacement of the fuse |
| Transformer. | Hoodling, smell of burning | Inter-turn closure | Transformer replacement |
| USB-port | No contact, staggering. | Mechanical wear and tear | Port soldering |
Assembly and sealing of the device
After the repairs, you need to reassemble the device, if the plastic fixtures are broken during the dismantling, you need to use glue, and for this purpose, cyanacrylate glue or a special glue for plastic that does not conduct current is best suited.
Put a thin layer of glue around the perimeter of one of the halves of the case, and it's important to keep the glue from getting inside the board or the contacts. USB-Put the halves of the body together and hold them tightly together, and you can use rubber rings or vise for drying out for better fixation.
Complete polymerization of the adhesive takes from 12 to 24 hours, so it is strongly recommended not to include the device in the network before this time in order to avoid short circuit.
Check the reliability of the assembly by slightly shaking the device in your hands, if you hear the knocking of the internal components, then the board is not fixed properly, in which case you will have to repeat the dismantling and add fixing elements, such as pieces of foam or shrinkage.
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High-quality sealing of the housing after repair is critical for the safety of the charger.
Common mistakes in self-repair
One of the most common mistakes is ignoring safety rules when working with high voltage. Many users forget that capacitors can store charge for a long time. Touching the current part under voltage can lead to serious injury.
Another mistake is the use of inappropriate tools, which means that trying to open the case with a thick screwdriver or kitchen knife often destroys the plastic case, making the device unusable even after successful electronics repairs.
It's also common to neglect to check components before assembly, and installing a new part without finding out why the previous one failed can cause it to burn again, for example, if the fuse is burned because of a diode failure, replacing only the fuse will cause it to burn out instantly.
- ❌ Ignoring discharge of capacitors.
- ❌ Use of brute force in autopsy.
- ❌ Lack of verification of related components.
- ❌ Use of conductive glue.
When repairs don’t make sense
There are situations where disassembling Xiaomi's charger on its own is not feasible. If the main control chip is burned or the transformer is damaged, the cost of replacing these components with work may exceed the price of the new original adapter.
In addition, if the housing of the device has suffered serious mechanical damage or has been exposed to water, it is almost impossible to restore its leakage, and the use of such a charger becomes dangerous, as the risk of electric shock or fire increases.
Should old chargers be repaired?
In case of doubts in your abilities or lack of necessary equipment, it is better to contact a specialized service or purchase a new device.The security of your home and expensive Xiaomi equipment is more important than saving on the purchase of a new power supply.