Xiaomi Mijia series leads deservedly gained popularity due to stylish design and long-term autonomous work, but even reliable electronic devices require maintenance over time. Most often, owners face degradation of the lithium battery, which stops holding the charge, or mechanical damage to the power button. Self-replacement of power cells allows you to extend the life of the gadget without the need to buy a new device.
The opening process requires care, because the design is made using hidden screws and adhesive joints. The tightness of the case is a key factor in protecting the electronics from moisture and sweat during training. Disassembly technology can lead to loss of moisture protection, so it is important to strictly follow the algorithm of actions and use the right tools.
In this article, we will take a closer look at the steps of dismantling, the tools you need, and the common mistakes you should avoid, how to safely remove the battery, replace it with a new battery, and properly assemble the device back, and attention to detail at each stage ensures a successful repair result.
Tools and workplace preparation required
Before starting work, you need to organize a well-lit workplace with a flat surface. To disassemble the Xiaomi Mi Smart Pet Water Fountain or leash requires specific tools that are found in any home craftsman's kit or easily bought in electronics stores. Lack of suitable equipment can damage plastic latches.
The main tool will be a thin metal blade or a special mediator for opening the cases. Plastic cards are ineffective here, because it requires a significant effort to overcome the resistance of the glue, you will also need a set of small diameter cross screwdrivers (usually PH00 or PH000) and tweezers for working with small plumes.
To work with adhesives, you need a heat source. A hair dryer or heating platform will help soften the adhesive that holds the halves of the body together. Do not use an open fire, as this is guaranteed to melt the plastic and damage the internal components.
- 🛠️ Thin metal spatula or scalpel
- 🔋 soldering iron and solder (to replace the battery)
- 💨 Hair dryer for body heating
- 🧲 Magnetic screw mat
⚠️ Warning: Before starting any work, be sure to completely discharge the device before turning off to minimize the risk of short circuit in case of accidental damage to the contacts.
The algorithm for opening the leash body
Disassembly begins with a close inspection of the outer surface for visible screws. Most Xiaomi models have attached attachments hidden under decorative plugs or rubber linings in the strap attachment. Carefully tuck these elements with a blade to access the screw joints.
After you unscrew all the visible screws, the main (call) is a glue seam around the perimeter of the device. Heat the body with a hairdryer to about 60-70 degrees Celsius, evenly warming all sides. The plastic should become warm, but not hot, so as not to deform.
Insert a thin blade into the junction of the halves of the body and slowly lead it along the seam, while pushing the halves apart with a mediator. Movements should be progressive, without sharp jerks that can break the internal plastic latches. If the body resists, repeat the heating procedure.
☑️ Pre-mortem checks
After successfully disconnecting the halves, don't immediately try to split them wide. Inside, there may be a plume connecting the main board to a button or an LED indicator, carefully examine the insides and, if necessary, disconnect the connectors with tweezers.
Battery replacement and contact soldering
The centerpiece inside the case is a lithium polymer battery, which most often fails. In older models, it can be soldered to the board with wires, in new ones, it is connected through a connector. To replace it, you will need a soldering iron with a thin sting and electronics skills.
Carefully unfurl the old battery while observing polarity. Red wire usually corresponds to plus (+), and black wire corresponds to minus (-). Misconception of polarity when installing a new battery can lead to instant failure of the power controller.
The new battery should have the same dimensions and voltage (usually 3.7V). If the battery is too thick, it can be carefully disassembled by removing a soft bag with an electrolyte, and inserted into the home body, observing precautions.
How to choose a new battery?
| Parameter | Original | Replacement | Impact |
|---|---|---|---|
| Tension. | 3.7V | 3.7V | Critically. |
| Capacity | 200-500 mAh | Any higher. | Time to work. |
| Dimensions | Precisely. | Less or equal | Assembly of the hull |
| Jack | 2-pin | Compatible | Connection |
Repair of the switch and loops
A frequent problem is sticking or failing the power button. A mechanical switch is placed on the board and oxidizes with moisture over time. Repairs don't always require a complete replacement of the component, sometimes just clearing the contacts.
Use isopropyl alcohol and a soft brush to clean the area around the button. If the button is mechanically damaged, it should be soldered out and replaced with a similar one with the same dimensions.
Check the plumes that connect the various modules, they can rub or oxidize, carefully wipe the contacts of the plumes with a blower or alcohol, when assembled, make sure that the plumes are not clamped and have no clamps.
- 🧹 Cleaning contacts with alcohol
- 🔍 Checking track integrity
- 🔌 Replacement of connectors during oxidation
- 🔧 Scotch plume fixation
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Use high-purification isopropyl alcohol (99%) as it evaporates quickly and leaves no conductive traces on the board.
Assembly of the device and checking leakage
After successful replacement of components, you need to assemble the device in reverse order. Before the final gluing, test the battery by connecting to the board. Make sure that the device responds to the press of the button and the charging indicator lights up.
To restore tightness, use a special electronics glue sealant (such as the B-7000) or double-sided tape for smartphones. Apply a thin layer of glue around the perimeter of one of the halves of the case.
Connect the halves of the body and tightly press them together. Lock the device with rubber harnesses or clamps while the glue is drying (usually 1-2 hours), and remove the excess glue that has protruded outside carefully with a dry wipe.
⚠️ Warning: Do not turn the device on immediately after gluing, allow the sealant to be fully polymerized within a day, otherwise the water protection will be disturbed and the device may fail on the first use.
Common Errors and How to Resolve Them
When you do your own repair, it's easy to make mistakes that can cause you to break, and one of the most common is that you get a plume damaged when you do a careless opening, and you have to be very careful when you use metal tools next to flexible joints.
Another common mistake is to use the wrong glue: Superglue (cyanacrylate) becomes brittle over time and can evaporate, forming a white plaque on optics or sensor lenses. Use only specialized formulations.
If the device doesn't turn on after assembly, check the polarity of the battery connection and the integrity of the soldering, maybe the wire was squeezed during assembly or the connector was forgotten, and multimeter diagnostics will help find the circuit break.
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The secret to success is patience and precision when dealing with small parts, and rushing almost always damages plastic or electronics.