Modern automatic cleaning devices such as the Xiaomi Mijia Robot Vacuum make life much easier but require maintenance over time. Many owners face situations where standard filter cleaning and sensor wipes are not enough. Noise, loss of suction power or getting stuck on carpets often indicate the need for deeper intervention in the internal mechanics of the device.
Disassembling a robot vacuum cleaner is a process that requires accuracy, understanding the electronics and having the right tools. Mistakes can damage plumes or impair the sealability of the body. In this article, we will take a closer look at the process of dismantling popular Mijia models so that you can safely reach the main nodes to clean or replace components.
Before you start, it is important to realize that opening the case can void the manufacturer's warranty obligations. However, if the warranty period has already expired, self-repair becomes an economically viable solution. It is critical to completely disconnect the device from the charging station and turn it off before any manipulation of the case.
Tools and workplace preparation required
To properly disassemble a robotic vacuum cleaner, you need a minimal but specific set of tools. Using inappropriate screwdrivers often leads to slicing of the screw faces, which makes simple repairs a difficult task to drill the fastener.
You will need cross screwdrivers of different sizes, a plastic spatula (spooder) to open latches and tweezers to work with small parts. Also, it will not be superfluous to sort the screws, since Xiaomi designs use fasteners of different lengths, and it is very easy to confuse them.
- 🔧 Precision screwdriver set (PH0, PH1) for twisting the screws of the body and modules.
- 🛠️ Plastic card or mediator for neat separation of body parts without scratches.
- 🧲 Magnetic mat or tray with sections for sorting screws of different types.
The organization of the workspace is the key to success. The light must be bright and directed so that the shadows do not hide the small fasteners under decorative linings. The vacuum cleaner should be on a flat, clean surface, where the small details do not get lost in the pile of the carpet or roll under the sofa.
⚠️ Warning: Never use metal objects (knife, stiletto) to tweak the lids of the case, as this is guaranteed to damage the plastic and can lead to short circuits when accidentally touching the board.
☑️ Preparation for disassembly
Primary dismantling of external elements
The disassembly process begins with removing removable modules that do not require the use of a screwdriver, first removing the main container for dust and water (if the model supports wet cleaning), which opens access to the HEPA filter and brush, which also need to be removed for later cleaning or replacement.
And if you flip the device over, you'll see the main turbo brush attached to the sides with plastic plugs, and you'll have to pull the locking tongues and remove the shaft to remove it. Often, that's where the most hair and wool accumulates, which causes the engine to overload, and you'll also remove the side brush, which is usually held on a single screw or latch.
The front rotary support and the two main driving wheels often require cleaning of the coiled hair. The driving wheels in Xiaomi Mijia models often have a complex mounting system and can be covered with decorative linings that need to be carefully tampered with.
- 🌀 Remove the main dust collector and rinse it with water, completely drying before installation.
- 🧹 Remove the main brush, clean the shaft bearings from the hair and check the bristles wear.
- 🛞 Check the free movement of the front wheel and the absence of foreign noise in the bearings of the driving wheels.
Once all the removable elements are removed, you can start to unscrew the visible screws on the bottom panel, which range from 4 to 8 depending on the specific modification of the robot. Some screws can be hidden under rubber linings or stickers, so carefully examine the surface.
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Before removing each module (such as a wheel or sensor), take a photo of its connection, which will help to properly assemble the device back without confusing the plumes.
Disassembly of the main body and access to electronics
Once all screws are removed from the bottom, you have to detach the top cover, and the robot vacuum cleaner is built on a set of plastic latches that are located around the perimeter, and you have to use a plastic blade to unlock them, gently passing between the top and bottom of the body.
Don't try to break the halves of the case dramatically, as they are connected by plumes inside.The top panel usually contains a laser rangefinder (LDS), an on button and indicators that are connected to the main board by thin wires.A sharp jerk can break these connections, leading to expensive repairs.
Inside, you'll see the main circuit board, the battery pack, and the wheel motors. The battery in Mijia models is most often represented by a multi-piece 18650, a closed plastic casing, and it often requires the contacts to be soldered off or the lock-protected connector to be removed.
| Component | Location. | Type of attachment | Frequency of service |
|---|---|---|---|
| Main engine | Central part | Screws + rubber dampers | As the noise comes along |
| Laser module (LDS) | Top cover. | Train + screws | If the card is wrong |
| Collision sensors | Front bumper. | Latchers | When the button sticks |
| Wheeled modules | Bottom panel. | Screws + connector | When you slip. |
Access to internal electronics opens up the possibility of cleaning contacts and checking the integrity of wiring. Often, charging or communication problems are caused by oxidation of contacts or a fracture of a wire at the bend site. Visual inspection of the board reveals swollen capacitors or traces of moisture.
Why does the robot eat after assembly?
Maintenance of navigation system and sensors
The navigation system is the brain of your smart vacuum cleaner. In laser rangefinder (LDS) models, the condition of the rotating module at the top is critical, and inside it is a laser and a motor that rotates the tower. Over time, the lubricant in the motor bearing dries out, causing a characteristic creak or stoppage of rotation.
To maintain the LDS module, you need to carefully remove the protective cap and the plastic ring. Inside you will see a motor with gears. A drop of silicone oil or a special lubricant for plastic can extend the life of this unit for several years, the main thing is not to overdo it so that the oil does not fall into the laser prism.
The elevation and collision sensors are located around the perimeter of the lower part and on the bumper. They are infrared diodes that can get polluted by dust. Rubbing them with soft cloth without pile often solves the problem when the robot begins to "fall" from carpets or ram walls.
- 🔦 Wipe the transparent windows of the height drop sensors with a soft microfiber.
- 🔄 Lubricate the rotation axis of the laser module with drops of liquid silicone lubricant.
- 🧹 Blow the sensor holes with compressed air to remove fine dust.
If the laser module stopped rotating or cracked, the laser head or the motor itself may have failed, in which case the entire assembly must be replaced, since calibrating the laser at home is almost impossible without special equipment.
⚠️ Attention: It is strictly forbidden to wipe the laser lens with alcohol or aggressive chemistry, this can cause clouding of the plastic and loss of scanning accuracy.
Battery replacement and wheel maintenance
Reducing battery life is a natural aging process for lithium-ion cells. If your Xiaomi Mijia has started returning to base without cleaning the apartment, or only works for 10-15 minutes, a battery replacement is required. Most models require a battery pack encased in a plastic case with an electronic control board (BMS).
To replace, you need to disconnect the power connector from the main board. Be careful: wires can be short, and excessive tension will lead to their breakage. New batteries for robot vacuum cleaners often have higher capacity than the standard, which allows you to increase the area of retractable area in one cycle.
Wheel modules are also consumables, and they have gearboxes that wear out over time or get clogged with dirt, and if the wheel is freely spinning but humming when it's working, or if it's tightly turned, it needs to be removed and cleaned, and often it's enough to remove the wound hair from the axle and lubricate the mechanism.
When assembling wheel modules, it is important not to overtighten the mounting screws, as the plastic case of the gearbox may crack, and also make sure that the connectors are connected correctly to the board, since the polarity in some models is not protected from error.
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The battery life is on average 2-3 years of active use, and the use of original or certified analogues will ensure stable operation of the power management system.
Device assembly and initial start
The assembly is done in reverse order, but requires increased care to lay the plumes and wires. They should not fall under the screws or into the rotation zone of the mechanisms, otherwise, the first time you turn on, you will short circuit or mechanical damage. Make sure that all connectors are snapped to the characteristic click.
When you twist the screws on the bottom cover, keep the tightening uniform. Don't twist one screw to the end, leaving the others free. It's better to make all the screws first, and then gradually tighten them diagonally to avoid skewing the body and the appearance of gaps.
After assembly, install the dust collector and side brush, then put the robot on the base. The indicator should light up, signaling the start of charging. If the device emits an error signal or does not respond, you need to check the connections of internal components again.
The first start after disassembly is better controlled visually, make sure all motors are running, the laser is rotating, and the robot builds a map of the room correctly. If you've changed the main nodes, you may need to reset the map through the Mi Home app.