How to Disassemble Xiaomi Charger: The Complete Guide

Xiaomi smartphone owners often face a situation where the original power supply stops working correctly or requires replacement. The charger is a complex electronic component, inside which are located chips, capacitors and transformers. Understanding how this accessory is built is necessary not only for repair, but also for assessing the quality of the purchased product.

Disassembling the power supply is a process that requires care and understanding of risks. There may be residual voltage inside the circuit that is dangerous to humans even if the device is disconnected from the grid, which is why it is important to know what elements you are dealing with and how to organize the workplace correctly before you start any manipulations.

In this article, we will take a closer look at the design of Mi chargers, break down typical breakdowns, and explain why manufacturers make cases indissoluble, what tools will be needed to accurately open and what to look for when diagnosing internal components.

Design and features of Xiaomi power supplies

Modern chargers from Xiaomi and sub-brands like Redmi or Poco are made in a monolithic case, which is not chosen by chance: it provides high sealability, dust protection and mechanical strength. Inside the plastic casing hides a printed circuit board with densely spaced elements.

The core is a pulsed voltage converter that transforms the network's 220 volts into safe 5, 9, 12 or 20 volts to charge the gadget. The key element is the power controller, which controls the power transfer process and supports Quick Charge or Power Delivery fast charging protocols.

The design feature is the absence of visible screws on the outside of the case, which manufacturers use ultrasonic plastic welding or tight fitting of parts with internal latches, which makes the opening process laborious and often leads to damage to the appearance of the device.

⚠️ Attention: Opening the charger deprives you of accessory warranty, and the violation of the integrity of the housing reduces the protection against electric shock.

To successfully disassemble, you'll need to understand where the main nodes are. A transformer usually occupies the center of the board, and the input and output capacitors are located at the edges. With a sample diagram, it's easier to guess where the mounting points might be.

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Use a magnifier or macro shot on your phone to consider the chip marking before starting disassembly – this will help you find the device’s diagram on the Internet.

Necessary tools for safe autopsy

To open Xiaomi charging without critical damage, a regular set of screwdrivers will not be enough. You will need specialized tools to work with small parts and tightly seated plastic.

The main tool will be a thin blade or a special mediator to open the housings, you also need a hair dryer to soften the glue if the body is welded, you can do without antistatic tweezers and magnifying glass to work with small components.

Here is a list of what to put on your desk before you start:

• 🔧 Thin flat screwdriver or metal mediator for sutures.
• 🌡️ Building hair dryer or powerful household hair dryer for heating the body.
• 🔪 Stationery knife with a new blade for neatly cutting the seam.
• 🧤 Dielectric gloves to protect hands and prevent static discharge.

It's important to use dielectric tools, and metal objects can accidentally close contacts on the board if the capacitors are still charged, and safety is more important than speed.

If you plan to not just open but also assemble the device back, stock up on thin superglue or double-sided tape. Native latches after opening may not hold the case tight enough, leading to backlash or extraneous sounds when working.

Step-by-step instructions for disassembling the body

The opening process begins with a visual inspection of the seam connecting the two halves of the plastic case, and in most Xiaomi models, this seam runs around the perimeter of the device, and your task is to find a weak spot or a technological gap.

First, heat the body with a hair dryer. The temperature should not be extremely high, 60-80 degrees Celsius is enough, and this will soften the plastic and possibly melt some of the adhesive if it was used in the assembly. You need to heat it evenly from all sides.

Once heated, take a thin blade and gently insert it into the seam. Movements should be forward, along the junction line, rather than perpendicular upwards, so as not to break the plastic guides. Walk the blade around the perimeter, gradually increasing the gap.

When the gap is sufficient, use a plastic mediator or credit card to finally untie the halves. If the body is held to ultrasonic welding, you'll have to apply a force that almost always leaves traces on the plastic.

Once the lid is removed, you will have access to the PCB, and at this point it is important not to move too fast, because the components can only be soldered, and carefully examine the insides for obvious defects.

Diagnostics of internal components and malfunctions

When you open the case, you'll see a compact electronic circuit, and the main components that fail are the input capacitors, the fuse, the output diodes, and visual inspection often reveals the problem without using a multimeter.

First, look at electrolytic capacitors, and if they're swelling or leaking out of an electrolyte, the device won't work, and check for soot on the board, which is a sign of short circuits or overheating.

• 🔍 Safety: Often burns out when voltage surges in the network, its integrity is easy to check visually (the thread inside must be intact) or the vertebrae.
• 🔌 Jack USB: Mechanical damage to contacts or rotting contacts from the board is a common cause of lack of charge.
• 📉 Transformer: Rarely fails, but when insulation breaks down, it emits a burning smell and can hum.

If there's no external damage, you'll need a multimeter to vertebrate the circuits. Start with the input: check if the voltage comes on the board after the fork. Then check the output, but remember that without a grid connection, there should be no voltage.

⚠️ Warning: Never touch the elements of the board connected to the 220B network. Even a brief touch of the current parts of the input circuit can lead to an electric shock.

Pay special attention to the condition of soldering. In low-cost models or after heavy heating, the contacts may go away.Cold soldering looks like a dull, uneven tin around the leg of the part. Warming up and adding solder often solves the problem.

Electrical safety measures when working with a fee

The pulsed power supply risks electric shock, and the main danger lies in the high-voltage part of the circuit, which is separated from the low-voltage (USB output) galvanic interchange.

Even after disconnecting from the socket, the inlet filter capacitors can still have a charge of several hundred volts, a charge that can last for hours, and the capacitors must be forcibly discharged before touching any of the circuit board elements.

To discharge, use a resistor with a resistance of several kiloomes or a light bulb, connecting them to the contacts of the capacitor, the spark and the characteristic click will confirm that the energy has gone, only then you can safely touch the components.

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The main safety rule is to always discharge the input capacitors before touching the board, even if the device has been disconnected from the network for a long time.

Use a dielectric mat on a desk and work in a dry room. Humidity reduces skin resistance and increases the risk of electric shock when accidentally touched. If you're not sure about your electrical skills, you'd better limit yourself to visual inspection.

Should the charger be repaired?

The question of whether Xiaomi charging repairs are worthwhile is one of the most expensive, and the cost of a new certified accessory is often comparable to the cost of repairs in the service.

If the breakdown is to replace the fuse or solder the USB connector, repair makes sense. These components are cheap and take a little time to work, and you can restore the functionality of the device for pennies.

But if the control chip is burned or the transformer is broken, repairs become economically unprofitable, the cost of components can exceed the cost of a new unit, and it can be difficult to find original chips for Xiaomi charging protocols.

And you also have to consider that when you open it, it's not leaky, it's more vulnerable to moisture and dust, and if you live in a high-humidity region, the open board can oxidize faster than the new charger burns.

Frequently Asked Questions (FAQ)