Xiaomi’s Wiha Mijia smart electric screwdriver has proven itself to be a reliable tool for small household repairs and electronics assembly.However, even quality appliances require maintenance or replacement of consumables such as bits or internal drive components. Owners often face the question of how to properly dismantle the device without damaging thin plastic latches or a magnetic mechanism.
The process of disassembling this gadget has its own technical nuances, which are important to consider to preserve warranty and functionality. The design of the case is designed according to the scheme of "sandwich", where there are no visible screws on the external surface, which often puts inexperienced users at a loss. In this article, we will look in detail at the algorithm of actions, the necessary tool and precautions.
It should be noted that complete disassembly to the level of a PCB is extremely rare, usually to replace the battery or clean the contacts after moisture. In most cases, users need to know how to remove or replace the spindle and the locking ring. Xiaomi tool is designed with a high build density, so rush is unacceptable here.
Preparation of the workplace and the necessary tool
Before starting the dismantling, you need to organize a comfortable and well-lit workplace. Small parts such as locking rings and screws are easy to lose on the table, so it is recommended to use a magnetic mat or sorting tank. The main requirement is the cleanliness of the surface so that dust does not get inside the mechanism when opening the case.
You'll need a minimal toolkit that you often already have, and the key piece will be a thin PH00 or PH000 cross-stick screwdriver, because the screws inside the case have miniature hats, and you may need a plastic spatula (a spooger) or a mediator to gently open the case without scratching.
- 🛠️ Thin cross screwdriver (PH00/PH000) screw-up.
- 🔧 Tweezers with curved ends for extracting small washers and rings.
- 🧤 Antistatic gloves to protect electronics from static discharge.
- 📦 Container with cells for sorting screws of different types.
You should not use metal tools to tamper with parts of the case, as this can lead to chipped plastic or damage to the decorative coating. the aluminum case of the device is strong, but the paint coating is easily scratched. If there is no plastic blade at hand, it is better to use an old plastic card or a mediator.
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Use a magnetic mat or just a piece of paper with painted sectors so as not to confuse screws of different lengths when disassembling.
Dismantling the outer cover and access to the screws
The first step in dismantling the Xiaomi Wiha is to remove the top decorative cover that hides the fasteners. Many users mistakenly look for screws from the outside, not noticing that the top of the case is held on a tight landing and hidden guides. First, you need to remove the container for bits, if it is installed at the moment.
Carefully tuck the edge of the top cover with a plastic blade at the junction with the main body. The movements must be progressive, without sharp jerks, so as not to break the plastic locks. You will hear a characteristic click when the lid begins to move away from the base. Inside you will find four screws located around the perimeter.
⚠️ Warning: Do not use excessive force when removing the cover. If it does not respond, check if the bit is stuck in the cartridge, which can block the rotation of the mechanism.
Once the lid is removed, you'll have access to the main frame. It's important not to lose a small spring or washer if they happen to fall out when you dismantle them. The fasteners can be of different lengths, so remember their location or sort them out right away. Some screwdriver modifications may have additional sealing rings under the lid.
Disassembly of the main body and removal of the mechanism
After twisting the four locking screws, the main body of the Wiha Mijia splits into two symmetrical halves, and it is important to proceed with caution, as there are thin plumes inside that connect the power button, the charging port and the engine to the control board, and the sharp dilution of the halves of the body is guaranteed to lead to a break in the contacts.
Carefully dilute the halves of the body, having previously inspected the interior space for the presence of connecting elements. The control board is usually fixed to one of the halves of the body with additional screws or latches. To fully remove the motor and gear, you need to disconnect the connectors of the plumes, putting them up with a thin tool.
Inside the case, you'll see a compact gearbox that transmits rotation from motor to spindle, and often this is where metal dust and old lubrication accumulate, which can cause extraneous noise or power loss, and for deep cleaning, the gearbox mechanism can be removed entirely by unscrewing the appropriate guides.
- 🔋 The lithium-ion battery is located at the bottom and connected by a separate connector.
- ⚙️ Planetary gearbox requires regular lubrication for silent operation.
- 💡 LED backlight is fixed on the front panel and connected to a common board.
When working with the insides of the device, be careful with the lithium battery. Damage to the sharp tool can lead to fire or chemical burn. If the battery is swelled or damaged, it should be immediately replaced with an original or quality analogue with the same characteristics.
☑️ Pre-assembly check
Replacement of bits and maintenance of magnetic module
The most common operation that users perform is to replace standard bits with specialized ones or maintain a magnetic holder. Unlike conventional screwdrivers, Xiaomi Wiha uses a magnetic fixing mechanism that can weaken or become contaminated over time. To replace a bit, just pull the old one and insert the new one before clicking.
If the bit is stuck or the magnet is no longer held, you have to disassemble the spindle assembly, remove the locking ring that holds the shaft, and then you take the ring off and you gently knock it out or pull it out, giving you access to the internal magnet and the spring mechanism, and you remove the metal shavings and you restore the grip.
The screwdriver spindle is designed to work with S2 bits and 25 mm in length, and using longer bits can lead to jamming of the mechanism. This is a critical parameter, the violation of which can damage the locking mechanism. Always check the compatibility of consumables before installation.
⚠️ Warning: When knocking out the shaft, use a soft material (such as a wooden stick) so as not to deform the end of the metal rod.
To maintain the magnetic module, it is also recommended to check the condition of rubber seals, if they are provided by the design of your version of the device. They protect the insides from dust, which is an abrasive for rubbing parts. Regular cleaning and lubrication extend the life of the magnetic cartridge several times.
How do you make a magnet stronger?
Diagnostics and battery replacement
Reducing battery life is a common problem after years of use: Xiaomi Mijia Electric Screwdriver has a battery type 18650 or similar form factor, depending on the board revision. To replace it, you need to completely disassemble the case, as described in the previous sections, and access the bottom of the device.
The battery is connected to the control board via a connector or, in some older versions, through soldering. If you use a connector, the replacement is simple: disconnect the old cell and connect a new one. If the battery is soldered, you will need the skill of working with a soldering iron and patience to not overheat the adjacent components on the board.
| Parameter | Original | Analogue | Note |
|---|---|---|---|
| Type of element | Li-Ion 18650 | Li-Ion 18650 | High-current models only |
| Tension. | 3.7 V V | 3.7 V V | Permissible 3.6-3.8 V |
| Capacity | 1500 mAh | 1200-2000 mAh | Affects working hours |
| Jack | 2-pin JST | 2-pin JST | Check the polarity! |
When choosing a new battery, pay attention to current output. High-current batteries are necessary to ensure peak engine power when twisting tight screws. Using conventional office batteries can lead to rapid discharge and voltage drop under load, which will cause electronics error.
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Use only high-current batteries (High Drain) with a current output of at least 10A, otherwise the screwdriver will not be able to develop full power.
Device assembly and function testing
The Xiaomi Wiha is built in reverse order, but it has its own subtleties. The main rule is not to pinch the screws of the case to the end at once. First, make all four screws, make sure that the halves of the body are tightly and without gaps, and then evenly tighten them cross-to-cross, this will prevent skewing of the body and the appearance of creaks.
Before the final assembly, be sure to check the device's operation. Connect the plumes, insert the bat and press the power button. Make sure the engine rotates both ways (mode switching/short press), the backlighting and charge indication work. Only after a successful test can you hide the wires and close the lid.
Pay attention to the position of the sealing rubber bands, if they've been removed. They have to lie flat in their grooves, without any cracks; improperly installed gum can cause dust to enter or backlash of parts; the quality of the assembly directly affects the durability of the tool in real use.
- ✅ Check the free stroke of the switch button before closing the case.
- ✅ Make sure that the lighting diode is not covered with the details of the body.
- ✅ Tighten the screws evenly to avoid cracks on the plastic.
After assembly, it is recommended to run a charge-discharge cycle of the battery so that the power controller correctly calibrates the charge level. Leave the screwdriver on until full discharge, and then charge to 100% when turned off. This will help to avoid a situation where the indicator shows an incorrect percentage of residual energy.
⚠️ Warning: If there is any noise or vibration after assembly, immediately disassemble the device again. Most likely, one of the gearbox screws is not twisted or a foreign particle has hit.