Xiaomi Redmi Note 8 Pro is one of the most popular mid-range smartphones, which is still actively used despite the release of new models. NFC, It allows you to make contactless payments, read tags and transmit data over short distances, but many users face problems: the module stops working after a fall, the signal disappears for no apparent reason. where exactly NFC-The antenna in the Redmi Note 8 Pro and can it be repaired independently?
In this article, we will analyze the design of the smartphone in detail, show the exact coordinates. NFC-The module is on the board and in the case, and we will explain why it can fail, you will learn how to check the health of the antenna without disassembling the device, what tools you will need for diagnosis, and in which cases you should contact the service center. We will pay special attention to typical repair errors – for example, why replacing the back cover can kill you» NFC, And how to avoid it.
Redmi Note 8 Pro: Where to hide NFC-module
The Redmi Note 8 Pro (codenamed begonia) is equipped with the NXP PN80T chip, a combined controller that is responsible for NFC and Mi Pay. Unlike many other smartphones where the antenna is taken out separately, here it is integrated into a flexible plume that is attached to the motherboard, which saved space inside the case, but made the module more vulnerable to mechanical damage.
Physically. NFC-The antenna is located at the top of the back cover, under the plastic panel next to the main camera, and if you look at the smartphone, the antenna plume goes from the motherboard upwards, wrapping around the battery, and ends with a thin loop under the metal screen. It is important to note that the antenna is not a separate element – it is soldered into a flexible board, which is also responsible for highlighting the buttons and vibration motor.
- 📍 Exact location: upper left corner (when viewed with face), under the back cover, next to the main camera module.
- 🔧 Type of fastening: flexible plume soldered to the motherboard (connector) J4502).
- ⚡ Power: receives voltage directly from the main controller NXP PN80T.
- ⚠️ Vulnerability: when the body falls or deforms, the plume may move away or break.
Interesting fact: in some versions of the Redmi Note 8 Pro (for example, for the Indian market) NFC-The module is physically missing, although there are traces of support in the firmware, and you can check for the chip through an engineering menu or specialized applications like NFC Tools.
It looks like NFC-antenna: photo and diagram
To get a better idea of where the antenna is, let's take a visual look at it. In the photos of the disassembled Redmi Note 8 Pro, you can see that the NFC plume is a thin strip of gold contacts that goes from the motherboard to the top of the body, and at the end of the plume is the antenna itself, a small loop of copper foil twisted into a spiral.
Below is a simplified layout of the components (back view, no back cover):
| Component | Location. | Notes |
|---|---|---|
| NFC-antenna) | Top left corner, under camera | Sticked to the inside of the back cover |
| NFC connector on board | Next to the battery connector | Marking J4502 or NFC_CONN |
| NXP PN80T chip | Under a metal screen, next to the processor | Responsible for signal processing |
| Charging contacts (for contactless payments) | Lower part of the hull | Not related to NFC, but may affect signal stability |
In practice, the antenna looks like a thin black or transparent film with metallized tracks, and it is easy to damage if you disassemble it sloppy, so if you plan to repair your smartphone yourself, it is recommended to use plastic blades and avoid metal tools.
What happens if you break the NFC plume?
How to check the performance of NFC without disassembly
Before you disassemble a smartphone, you should make sure that the problem is really in the antenna, not in the software settings.
- Activate NFC in settings: Go to Settings → Connection and Sharing → NFC and turn on the switch. If the option is not available, then your version of the smartphone does not support NFC (for example, the global model for some regions).
- Check with the app: Install NFC Tools or NFC Check from Google Play. These programs will show whether the smartphone recognizes tags. If the app gives an error "NFC is not supported", the problem may be in the firmware or hardware.
- Real card test: Hold your contactless payment-enabled bank card to the top of your smartphone (where the antenna is located).If the device doesn't respond, try restarting it and try again.
- Checking the Engineering Menu: Enter ##4636## in the phone dialer, select Phone Information, and find the NFC section. If it is missing or shows the status of "Disconnected", this may indicate a hardware malfunction.
If all tests fail, but the NFC is displayed as turned on in the settings, the most likely problem is the physical damage to the antenna or plume, in which case you will need to disassemble the device.
Activate NFC customized|Check through NFC Tools|Testing with a bank card|Go to the engineering menu (#4636##)|Reboot your smartphone-->
Common Causes of NFC Failure
The NFC in the Redmi Note 8 Pro may stop working for several reasons, and not all of them are related to physical damage.
- 🔧 Software glitches: Often NFC It turns off after updating the firmware or resetting settings, in which case it helps to flash through Fastboot or reset to factory settings (but do not forget to back up!).
- 📱 Train damage: If the smartphone fell or was subjected to a strong vibration (for example, in a car), the flexible plume could move away from the connector on the motherboard.
- 🔋 Battery impact: Bloated battery can put pressure on plume NFC, This is one of the reasons why after the battery is replaced. NFC suddenly starts to work.
- 🛠️ Poor repairs: If the back cover or screen was previously replaced, the masters could damage the antenna or improperly connect the plume.
- 📶 External interference: Metal covers or magnetic holders can shield the signal NFC. Try to remove the cover and repeat the test.
An interesting nuance: in some cases, NFC stops working after upgrading MIUI to version 12.5+. This is due to a change in drivers for the NXP PN80T chip. The solution is a rollback to the old firmware or installing a custom recovery (for example, TWRP).
💡
If NFC is unstable (it appears, then disappears), try calibrating the antenna. To do this, in the engineering menu (#4636##), select RF Band Mode and set the Auto value.
How to Disassemble Redmi Note 8 Pro to Access NFC-antenna
If you're sure there's a hardware problem, you can try disassembling your smartphone yourself. Attention: this will void the warranty (if it's still valid) and require care. Here's a step-by-step guide:
- Tool preparation: You will need: plastic shoulder blades, PH00 cross screwdriver, tweezers, hair dryer (to soften the glue) and a screen suction cup.
- Removal of the back cover: Heat the edges of the body with a hair dryer (temperature ~60°C), then gently tuck the cover with a plastic blade, starting at the bottom corner. Be careful - there are plumes under the lid that can be damaged.
- Battery shutdown: After removing the lid, first disconnect the battery connector (it is at the bottom of the board) and this will prevent short circuits.
- Access to NFC-The antenna is attached to the motherboard with a connector J4502. Carefully disconnect it with tweezers, pulling on the black lock.
- Contact check: Check the plume for tears or oxidation. If the contacts are contaminated, clean them with alcohol and a soft brush.
If the plume is damaged, it can be replaced (the original spare part article — MDY-093). The average cost of a new plume is about 500-800 rubles. Note that when replacing the back cover, you often have to glue the antenna, because it is glued to the inside of the panel.
💡
When disassembling, never pull the NFC plume, it's very fragile. All manipulations are done only by the edges, avoiding pressure on the copper tracks.
What to do if the NFC is not working after repair
If you’ve tried to fix your smartphone before, but the NFC never worked, here are some tips:
⚠️ Note: If you have replaced the screen or back cover NFC It stopped working, probably the master damaged the antenna plume, and 90 percent of the time, the problem is solved by reconnecting the connector. J4502 motherboard.
- 🔄 Reconnect the plume: Sometimes the contacts oxidize or don't fully enter the connector. Carefully remove and insert the plume back, making sure the lock is snapped.
- 🔧 Check the firmware: If NFC Disappeared after the update, try to roll back to the previous version MIUI Fastboot. Instructions are on the forums. 4PDA or XDA Developers.
- 📡 Testing with another SIM-CASE: In rare cases, problems with NFC related to the conflict between SIM-map and module NXP PN80T. Try inserting a card of another operator.
- 🛠️ Diagnostics in the service: If nothing helps, it is possible that the chip itself is damaged NXP PN80T. Its replacement requires rationing and costs about 1500-2500 rubles.
Note that in some cases, NFC may not work due to conflict with custom firmware (such as LineageOS or Pixel Experience).