Installation of fingerprint scanner on Xiaomi: instructions from A to Z

The fingerprint scanner has become an integral part of modern Xiaomi smartphones, providing fast and secure access to the device. However, not all models are equipped with this module out of the box, and in some cases, users face the need to replace or install the sensor themselves - for example, after repairing the screen or buying a used device without a scanner. This article will help to understand how to properly integrate the fingerprint scanner into the Xiaomi body, connect it to the motherboard and configure it in the system.

It is important to understand that the procedure varies depending on the smartphone model and the type of scanner (optical, ultrasonic, capacitive).We will look at the universal steps relevant to most Redmi devices, POCO And the Mi line, and also pay attention to the critical nuances that the manufacturer is silent in the official documentation. If you have never dismantled the smartphone, it is better to contact the service center, as errors in the installation can lead to damage to the plumes or failure of the motherboard.

1. Compatibility of fingerprint scanners with Xiaomi models

Before you buy a new sensor, make sure it fits your model.Figurative scanners at Xiaomi fall into three types:

• 🔹 Capacitive - the most common, installed under the display glass (for example, in the Redmi Note 10 Pro or POCO X3 Pro) Require precise calibration after installation.
• 🔹 Optical – use light to scan the fingerprint (found in Mi 11 or Redmi) K40). More resistant to damage but sensitive to pollution.
• 🔹 Ultrasonics are the most advanced, scanning the print through sound waves (used in flagships, for example, Xiaomi 13 Ultra.

Check compatibility by sensor article (printed on the module itself) or by service manuals. For example, the scanner from Redmi Note 9 Pro (model) FPC1035) not fit for POCO F3, Even if they look similar, use the table below for an indicative selection:

If you buy a scanner on AliExpress or other sites, pay attention to reviews — often sellers indicate the wrong items. The best option is to remove the old sensor and order a similar one for its labeling.

Installation tools and materials

To replace the fingerprint scanner, you need a specialized tool, so don't try to do anything at hand, because it can damage the plumes or the chips.

• 🔧 Plastic blades (for careful tweaking of the case and plumes) Metal tools should not be used!
• 🔧 Thermoair station or hair dryer (to soften the glue under the display if the scanner is integrated into the screen).
• 🔧 Tweezers with thin ends (for working with small connectors).
• 🔧 Multimeter (to check the scanner's power circuits before connecting).
• 🔧 Double-sided tape or glue B7000 (fixing).

Also prepare:

• 📱 Spare battery (if you plan to work for a long time with power turned off).
• 🔌 USB-charging cable (to test the scanner after installation).
• 🧴 Isopropyl alcohol (90%+) (clean-up).

If the scanner is installed under the display (as in most modern models), you will need a complete dismantling of the screen.

• 🛠️ Screen suction cups (2 pieces).
• 🛠️ Display separation mediator (plastic card or specialized tool).
• 🛠️ Screen protection film (so as not to scratch during dismantling).

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Before starting work, take a picture of the location of all plumes and screws - this will save hours when reassembling.

3. Dismantling old fingerprint scanner

The process of removing the sensor depends on its location. Let's look at two common scenarios:

Scenario 1: Under-display scanner (capacitive/optical)

This type of scanner is found in the Redmi Note. 10/11, POCO X3/X4 and other models with a built-in sensor in the screen.

1. Turn off your smartphone and remove it. SIM-map.
2. Heat the display edge with a hairdryer (temperature) ~60°C) during 2-3 minutes to soften the glue.
3. Carefully apply a plastic spatula to the screen, starting at the bottom edge, and use suction cups to keep your suction cups up evenly.
4. Disconnect the display and battery plumes (by pre-disabling the battery!).
5. The fingerprint scanner is usually located under the screen, a display plume, and disconnect it with tweezers.

Scenario 2: Scanner on the back or power button

Relevant for older models (Redmi) 5/6, Mi A2) or devices with a physical button scanner (POCO F1).

1. Remove the back cover, undercoating it with a plastic spatula (no need to heat).
2. Unscrew the screws that fix the metal plate above the scanner.
3. Carefully disconnect the sensor plume. In some models, it's soldered to the board, you'll need a soldering station.

⚠️ Note: If the scanner is soldered to the motherboard (as in Xiaomi Mi 8), it requires soldering skills to dismantle it. BGA-I'm not going to have experience, but I'm going to have to trust the professionals to do this, because the risk of damage to the board is over 70%.

4. Installation of a new scanner and connection

Before installing the new module, be sure to clean the contacts on the motherboard and the scanner itself with isopropyl alcohol. Even microscopic contamination can lead to unstable operation of the sensor.

Installation algorithm:

1. Place the new scanner in the socket, making sure that it fits tightly to the body (for underscreen models – to the display).
2. Connect the plume to the motherboard connector, and it should snap with a click, and don't push too hard, you can damage the contacts.
3. Secure the scanner with double-sided tape or glue B7000 (for rear sensors, screws).
4. Make sure that no cables are clamped or in contact with metal elements of the housing.

For models with a built-in screen scanner:

• 📱 Before gluing the display, check the sensor by plugging the battery and turning the phone on in Fastboot Mode (hold Volume Down). + Nutrition).
• 📱 Use new adhesive for display - the old one loses properties after heating.

⚠️ Warning: If the scanner does not respond to touch after installation, check:

• 🔌 Correct connection of the plume (reconnect it).
• 🔌 Integrity of contacts on the board (if necessary, sell off).
• 🔌 Firmware compatibility (sometimes software updates are required).

5. Scanner setup in the system MIUI

After the mechanical installation, you need to activate the sensor in the software.

1. Turn on your smartphone and go to Settings → Passwords and security → Fingerprint.
2. If the option is inactive, update the firmware through Settings → The phone. → Updating the system.
3. Follow the instructions on the screen to add a fingerprint. Touch the scanner from different angles to improve recognition.

In some cases (especially after being replaced by a non-original sensor), the system may give an error "failed to add a fingerprint."

• 🔄 Reset the security settings in Settings → Passwords and security → Additionally. → Fingerprint reset.
• 🔄 Install custom restoration (TWRP) and flash the persist module (requires an unlocked bootloader).
• 🔄 Reverse to an older version MIUI (If the problem occurs after the update).

For models with an ultrasonic scanner (such as the Xiaomi 13 Ultra), additional calibration may be required via the engineering menu:

#4636## → Testing equipment → Fingerprint Test

If the scanner is unstable (recognizes the fingerprint once in a while), try:

• 📱 Remove and add the print again.
• 📱 Clear the system cache in Settings → Memory. → Cleanup.
• 📱 Disable energy saving for com.android.biometrics (via Settings) → Battery → Battery mode).

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If the scanner is not recognized by the system even after installation is correct, the problem may be a damaged connector on the motherboard, in which case a diagnosis is required at the service center.

6. Frequent errors and their elimination

Even with a careful installation, users face typical problems.

⚠️ Note: If after replacing the scanner, the smartphone stopped turning on or stuck on the logo MI, You probably damaged the display plume or battery contacts. Don't try to turn the device on again, this may lead to a short circuit.

To diagnose hardware problems, use the test menu:

##36446337## → Fingerprint Test

If the test shows an error "FP Sensor: Fail, the problem with the sensor itself or its connection.

7. Alternative ways to unlock if the scanner is not working

If the scanner cannot be restored, alternative methods of unlocking can be used:

• 🔐 PIN-code or pattern lock – always set up a backup way to unlock!
• 🔐 Facial recognition (available in Settings) → Passwords and security → Facial recognition is less safe but convenient.
• 🔐 Smart Lock – Automatically unlock in trusted places (such as at home) or when connected to a trusted device (smart watches, Bluetooth headphones).

For models with Mi Band support, you can set the unlock through the bracelet:

1. Connect the Mi Band to your phone via the Mi Fitness app.
2. Activate the "Unlock Phone" option in the bracelet settings.
3. The phone will be unlocked when the bracelet is approaching (distance). ~1.5 m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m).

If you forgot. PIN-The code and the scanner are down, so you're gonna have to do a hard reset:

1. Turn off your smartphone.
2. Press Volume Up + Power before the Mi logo appears.
3. From the Recovery menu, select Wipe Data → Wipe All Data.

⚠️ Warning: Reset will delete all data on the phone, including photos and apps. If the device has activated the Find Device feature, after the reset, you will need to enter the information of the Mi Account associated with the phone.

FAQ: Frequent questions about installing a fingerprint scanner on Xiaomi