How to fix Xiaomi liquid soap dispenser: disassembling 7 typical malfunctions

Xiaomi’s automatic liquid soap dispensers (like the Viomi Smart Foam Soap Dispenser or Mijia Automatic Soap Dispenser) have become popular because of their convenience and hygiene. However, even the most reliable technology can fail: it stops responding to movement, does not emit foam, flashes the indicator or does not turn on at all, and 80% of the time, the problem can be fixed on its own without going to the service center.

In this article, we will analyze all the typical malfunctions of Xiaomi dispensers, from simple (blockage of the nozzle) to complex (breakdown of the infrared sensor or control board). You'll learn how to diagnose, what tools you'll need to repair, and where to buy parts if you need to replace them. V-SDS01) Add instructions for resetting settings through the Mi Home app.

Before you disassemble the device, check the obvious: whether the batteries are dead (if the dispenser is running on them), whether the soap is out, and whether the sensor blocks the movement of a foreign object. If everything is fine, proceed to a detailed diagnosis.

1. Diagnosis of malfunction: why the dispenser is not working

The first step is to identify what exactly broke, and the symptoms of the breakdown can be different, and each one indicates a specific problem:

• 🔴 Does not respond to movement of the hand → problem with an infrared sensor or power supply.
• 💧 Does not give out soap/foam → nozzle clog, pump breakdown or pipe breakage.
• 🔋 Blinking the indicator or not turning on → battery discharged, battery contacts oxidized, firmware failure (for "smart" models).
• 🔊 You hear a hum, but the soap doesn't go. → jammed the pump mechanism or broke the gear.
• 📱 Not connected to the Mi Home app → Failure of a Wi-Fi module or firmware.

For accurate diagnosis, perform simple tests:

1. Try manually pressing the pump (if the model allows it), if you have soap, the problem is with the sensor or the electronics.
2. Put a flashlight on the IR sensor (usually located in the front under the lid), and if the dispenser works, the sensor is fine, but it may be contaminated.
3. Check the battery voltage with a tester (should be at least) 1.2V on each element).

If you're not sure why after the checks, you'll need to move to disassembling the device.

• 🔧 Cross screwdriver (usually) PH0 or PH1).
• 🧲 Flat screwdriver or mediator to open the latch.
• 🧴 Isopropyl alcohol (for cleaning contacts).
• 🔍 Lupa (for inspection of small details).

2. Cleaning of nozzles and tubes: if soap is not issued

The most common problem is a clog of the sprayer or tubes. Over time, soap (especially thick or particle-filled) clogs the holes, and the pump cannot push the liquid through. V-SDS01) may also be swelled.

How to clean:

1. Remove the top cover (usually it unscrews counterclockwise or is held on latches).
2. Take out the soap container and rinse it with warm water.
3. Look at the nozzle, where the soap comes from. If you see a blockage, clean it with a needle or a toothpick.
4. Wash the pipe (if it is removable) under a stream of water or blow it.
5. For foam generator: remove the net (usually attached to the thread) and soak it in vinegar for 10-15 minutes.

If the clog is severe, use special means:

• 🧪 Citric acid (1 tbsp. spoon per glass of water) – pour into the tank for 30 minutes.
• 🧴 Isopropyl alcohol (70%+) — for cleaning plastic parts from fat.
• 🚿 Toothbrush - for mechanical cleaning of hard-to-reach places.

Important! Don't use abrasives (like soda powder) because they will damage plastic and rubber seals. Also avoid chlorine-containing liquids: they can eat gaskets.

3.Pump repair: if the dispenser is buzzing but not pumping

If you press a button or you trigger a sensor, you hear the motor buzz, but the soap doesn't go, the problem is the pump. 90 percent of the time, it's:

• 🔄 Jamming of the gear due to soap or dust.
• 🔌 Breaking the pump power wire.
• 🛠️ Wear of the membrane (in models with a diaphragm pump).

How to fix:

1. Disassemble the dispenser body (usually you need to unscrew 3-4 screws on the bottom cover).
2. Find a pump (black or white plastic block with wires).
3. Check the gears for blockages. If they're not rotating, clean them carefully with a cotton swab dipped in alcohol.
4. Call the wires with a tester (resistance should be 5-20 ohms). If a cliff breaks, solder a new wire.
5. If the membrane is torn, it must be replaced (parts are sold on AliExpress or in service centers).

In Mijia models MJ-SD01 viomi V-SDS01 The pump is mounted on latches, which can be easily removed for cleaning. If the dispenser still does not work after repair, check the control board (see section 5).

4. Replacement of the infrared motion sensor

If the dispenser doesn't respond to the hand, but the pump is working (checked by hand soap), the problem is the IR sensor. Xiaomi models typically use a sensor. TCRT5000 or.

Causes of breakdown:

• 💨 Sensor lens contamination (dust, soap spray).
• 🔌 Oxidation of contact on board.
• 💥 Failure of the sensor itself (burned out LED or photodiode).

How to fix:

1. Remove the front panel (usually it is held on the latches or one screw from the bottom).
2. Find the sensor – it looks like a small black or transparent plastic block with 3 legs.
3. Clean the lens with a cotton swab of alcohol. Blow the sensor hole.
4. Check the ration of the contacts. If they're oxidized, clean them up and solder them again.
5. If the sensor does not work, replace it with a new one. ~200-300 rubles on AliExpress).

In Viomi models V-SDS01 The motion sensor is combined with the control board, and it can't be replaced separately.

5. Power problems: batteries, battery, power supply

If the dispenser doesn't turn on or the indicator flashes, the first reason to check is power. Depending on the model, the device can work from:

• 🔋 Battery (usually) AA or AAA).
• 🔌 Network adapter (models with socket).
• 🔋 Built-in battery (e.g. Viomi) V-SDS01).

Diagnosis and repair:

1. For batteries, check the voltage with a tester. 1.2V — Also clean the contacts in the oxidation compartment (use an eraser or alcohol).
2. For network adapter: check the voltage at the output (should be 5V or 9V, If the adapter is defective, replace it.
3. For the battery: if the dispenser does not hold the charge, the charging controller or the battery itself may have failed. In Viomi models, the battery can be replaced with a similar one (18650 or 14500).

Attention! If the dispenser is running off the mains and it is short or sparkling, immediately disconnect it from the socket! This may indicate a capacitor failure or a short circuit on the board.

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To keep the batteries in the dispenser lasting longer, use alkaline batteries (such as Duracell or Energizer) that are less discharged in standby mode and better tolerate temperature changes in the bathroom.

6. Resetting and firmware for “smart” models

Xiaomi Dispensers with Mi Home (Viomi) Support V-SDS01, Mijia MJ-SD01 Pro) may glitch due to firmware failure or incorrect settings:

• 📱 Not connected to Wi-Fi.
• ⚙️ Does not respond to commands from the application.
• 🔄 Self-rebooting.

How to reset your settings:

1. Turn off the dispenser from power (remove the batteries or remove the plug from the socket).
2. Press the reset button (usually on the bottom panel or under the lid) and hold for 10-15 seconds.
3. Connect the power back. The dispenser should blink and emit an audible signal (if there is a speaker).
4. Connect to it via Mi Home as a new device.

If the reset did not help, try re-flashing the dispenser:

1. Download the latest firmware for your model from the Xiaomi Home website.
2. Unpack the archive and follow the instructions (usually you need to connect the dispenser to the PC on the computer). USB and use the MiFlash utility).
3. After the firmware, reset again.

Important! The firmware is only suitable for a particular model. The wrong firmware can permanently disable the dispenser.

7. Where to buy spare parts and when to contact the service

If self-repairing didn't work, you might need to replace the parts.

• 🛒 AliExpress is the biggest choice (look for the dispenser model) + "spare parts").

The cost of popular spare parts:

Contact the service is worth in cases:

• ⚡ Control fee problems (solding or chip replacement required).
• 💦 Leakage of soap inside the case (can cause corrosion of contacts).
• 🔥 Fire or melting of parts (hazardous for self-repair).

Average cost of repair in the service:

• 🛠️ Replacement of the pump - 500-800 rubles.
• 🔧 Replacement of the sensor – 400-600 rubles.
• 📱 Firming - 300-500 rubles.
• 🔋 Repair of fees - from 1000 rubles.

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If the dispenser is warranty (usually 1 year), do not disassemble it yourself - this will void the warranty.

FAQ: Frequent questions about repairing Xiaomi dispensers