Introduction: When a phone turns into a brick
Have you noticed that your Xiaomi is losing network every now and then? Calls don't go through, mobile Internet disappears, your phone says "No Service"? The problem is familiar to many owners of smartphones of this brand, from the budget Redmi to the flagship Xiaomi 14. But the root of the evil is: the fault of the firmware, "curved» SIM-card, hardware failure or communications operator?
In this article, we will not just list the possible reasons, but analyze them with reference to specific Xiaomi models (where this is critical), offer step-by-step solutions - from basic to advanced, and explain when it is worth carrying the phone to the service. And you will learn why some Xiaomi 2023-2026 years communication disappears due to an error in the module 5G, How to fix it without losing your guarantee.
Spoiler: 60 percent of the time, you can solve a problem yourself in 10 minutes, and let's start with the simplest one.
1.Problems with SIM-map: from oxidation to incompatibility
The first thing you need to check is yourself. SIM-Even if it was “working yesterday”, it does not guarantee that it is working today. Here are 4 typical malfunctions that Xiaomi can lose network:
- 🔹 Oxidation of contacts: moisture, sweat or time lead to corrosion of metal contacts on the surface of the metal. SIM-This is especially true for phones that are often used in high humidity conditions (e.g. Redmi Note 12 Pro).+ s IP53).
- 🔹 Incorrect pruning: if you cut nano-SIM from micro-SIM yourself, you could damage the chip.
- 🔹 Incompatibility with 5G: Some operators (such as Tele2) are issued SIM-Old-style cards that don't support new-generation networks. 13T or POCO F5 This is a “network search” without results.
- 🔹 Blocking by the operator: rare, but it happens that SIM Check the balance and status of the card in the operator's personal account.
How do you diagnose? SIM-Check the map and see it in good light, keep your contacts smooth, without any green plaque or scratches, and if you're in doubt, try inserting another one. SIM (For example, from another operator, check if the problem persists.
⚠️ Warning: Do not use alcohol or acetone to clean your contacts, they can damage the plastic; it is better to wipe the contacts carefully with a stripe (yes, regular school) or soft cloth.
Check the contacts for oxidation.|Try another one. SIM-map|Make sure the card is inserted correctly in the tray|Clean the contacts of the tray from dust-->
2. Network settings: what went wrong and how to return
If SIM-The map is fine, but the Xiaomi connection is still missing, and the fault may be the network settings, especially after updating the firmware or resetting to the factory settings:
- Network Mode: Go to Settings → SIM-maps and mobile networks → [yours SIM] → Type of network, if only it's worth it. 4G, and the operator supports 5G, The phone can get lost when you switch between towers (2G/3G/4G/5G).
- Operator Choice: In the same menu, tap Network Choice and wait for an automatic search. If the phone doesn't find your carrier, the problem may be in the firmware or communication module.
- APN-Settings: Incorrect access point parameters (APN) It causes the mobile Internet to work and calls to not (or vice versa). APN You can reset to default or enter manually (they are issued by the operator).
On some Xiaomi models (e.g. Redmi) 10C or POCO M5) Bug: After updating to MIUI 14 are lost VoLTE settings (voice through) 4G). That either keeps the calls up or they stop:
Settings → SIM- Maps and Mobile Networks → [your SIM] → Enable VoLTEIf the option is not activated in gray, it means that the problem is on the operator side (not all support VoLTE) or you need to update the firmware.
MTS|Beeline|Megaphone|Tele2.|Yota|Other-->
3. Programmatic failures: from MIUI before-break
Firmware MIUI — It's both a plus and a minus to Xiaomi, and it offers a lot of features, but it also has a lot of bugs, especially in the latest versions. If you lose the connection after the update, it's the software:
- 📱 Failure after update MIUI: For example, in Xiaomi 12T post-update MIUI 14.0.5 was massively lost due to an error in the modem driver.
- 🔄 Application conflict: some programs (e.g, VPN or network optimizers) block access to mobile data, check if there is a problem after installing new software.
- 🛠️ «Broken firmware: if the phone was flashed informally (for example, through Fastboot), the modem partition could be damaged.
How to diagnose a software failure?
- Launch your phone in Safe Mode (press the power button) → long tap on "Switch off» → «Safe mode. If it's working, it's the third-party app's fault.
- Check the error log: go to Settings → The phone. → Version. MIUI And you tap 5 times on the version number, and you'll open a developer menu where you can turn on the bug log.
⚠️ Note: If you are using your phone TWRP And then you lost the connection, never install firmware marked "Ported" or "Unofficial." They often contain incorrect drivers for Qualcomm or MediaTek modems.
How to roll back the update MIUI, if the connection is gone after him?
4. Hardware malfunctions: when without service can not do
If all the software methods have been tried and the Xiaomi connection is still missing, it's probably hardware. Here are the 5 most common malfunctions:
| Malfunction | Signs. | Xiaomi models, where it is more common | Cost of repair (approximately) |
|---|---|---|---|
| Damage to the antenna plume | Communication disappears when tilting the phone or pressing the body | Redmi Note 11 Pro, POCO X4 Pro | 1 500–3 000 ₽ |
| Failure of the modem chip | The phone doesn't see any of them. SIM-map, in the Settings blank IMEI | Xiaomi 11T, Redmi K50 | 3 000–8 000 ₽ (depends on the chip model) |
| Oxidation of contacts SIM-tray | The bond appears and disappears, especially after moisture is ingested. | Redmi 10A, POCO M4 Pro | 500–1 500 ₽ (cleaning + tray-change) |
| Power problems modem | The phone overheats, the battery quickly goes down, the connection disappears when the charge is low. | Xiaomi 12 Lite, Redmi Note 10 Pro | 2 000–5 000 ₽ (capacitor) |
How do you know if it's a hardware problem? Here are 3 key signs:
- Communication is lost physically: for example, when you press the top of the case (antenna plume) or after the phone falls.
- The phone doesn't see any of them. SIM-map, even knowingly working. → The phone. → General information is displayed empty fields IMEI or Model number.
- The problem appeared after moisture hit, even if the phone did not sink (high enough humidity in the room).
If at least one of the points coincides, do not waste time on software methods. Contact the service, and preferably an authorized Xiaomi, if the phone is warranty. Self-repair of an antenna module or a modem chip without experience is fraught with final failure.
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If the phone stops catching the net after falling or getting moisture, do not dry it with a hairdryer or in rice. Contact oxidation will accelerate, and repairs will become more expensive.
5.Operator-side problems: how to check and what to do
Sometimes it's not the phone that's the fault, it's the carrier's fault, and here are 4 scenarios where the problem lies on the provider's side:
- 📡 Planned work: the operator may shut down base stations for maintenance. SMS or in a private office.
- 📶 Network congestion: during rush hour (for example, in the evening in large cities), the quality of communication can deteriorate.
- 🔄 Billing failure: If you have some services connected (for example, “Unlimited Calls”), their failure can block outgoing calls.
- 🆔 Lockdown IMEI: If the phone is purchased in a “gray” way (for example, brought from abroad), the operator can block it. IMEI Roskomnadzor.
How do you check?
- Call your phone from another phone, and if you hear "subscriber temporarily unavailable," the operator's problem is.
- Check the network status on the operator’s website (section “Coverage map” or “Flaws Information”).
- Put it in. SIM-If there is no communication there, it is the operator's fault or SIM-map.
If the problem is confirmed, contact operator support. IMEI You may need to unlock through Roskomnadzor (if the phone is legally imported) or flashing it. IMEI (If the phone is grey, it violates the law).
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If the operator says that “everything works” but the communication is only lost in a specific place (for example, at home), try to force the choice of another base station. To do this, type in the dialer code ##4636#, select “Phone Information” and manually specify another network.
6. Features of specific Xiaomi models
Some Xiaomi smartphones have unique communication problems related to their hardware or firmware.
Xiaomi 13/13 Pro/13 Ultra: bug with 5G modem-overheating
The owners of the flagships of 2023 complain that when used actively 5G The phone loses its network and overheats, and it's caused by the unoptimized Qualcomm Snapdragon 8 Gen 2 modem driver:
- Turn it off. 5G In the network settings (save only) 4G).
- Update the firmware to the latest version (in) MIUI 14.0.12 bug fixed).
- If the problem persists, reset your network settings (Settings) → SIM-map → Resetting network settings).
Redmi Note 12 Pro+/POCO F5: conflict SIM-map
In these models, using two SIM-The connection to one of the cards (especially from different operators) may be lost due to the hardware feature of the MediaTek Dimensity 1080 modem:
- In the settings SIM-Disable Auto Network Selection and Set Manual Mode.
- Change it. SIM-maps in places (first) ⇄ second-second).
- Turn off VoLTE for one of the SIM-map.
Xiaomi 11 Lite 5G NE: mistake IMEI post-refresh
After updating to MIUI 13 Many users have experienced that the phone stopped seeing SIM-maps, and in the information about the device displayed IMEI: The reason is a failure when writing data to the nvram section:
- Make a backup copy. IMEI (if the phone still catches the network).
- Fastboot phone with full formatting (fastboot erase) modemst1 and fastboot erase modemst2).
- Restore. IMEI via the engineering menu (#36446337##).
⚠️ Attention: Recovery IMEI — A complex procedure that, if mistaken, can finally kill the modem. If you are not sure of your abilities, contact the service.
7. when to contact the service (and how not to run into scammers)
If you’ve tried all the methods, but the connection to Xiaomi is still missing, it’s time to carry the phone for repair. Here are 5 signs that you can not do without the service:
- 🔧 The phone doesn't see any of them. SIM-map, even after resetting the settings.
- 📱 The information about the device is displayed IMEI: unknown.
- 🔥 The phone overheats in the upper part of the case (where the modem is located).
- 💧 Before the problem, the phone fell into the water or was exposed to high humidity.
- 📉 The problem appeared after unofficial firmware or unlocking the bootloader.
How do you choose a service?
- Warranty repair: If the phone is warranty, contact only authorized Xiaomi service centers. the list can be found on the official Mi.com website.
- Non-warranty repair: look for services with good reviews (check on Yandex.Maps or 2GIS). Ask if they give a guarantee for work (good service gives at least 3 months).
- Cost: Before repairs, ask for diagnostics (usually free) and an estimate.Average prices: Replacement of an antenna plume: 1,500–3,000 ₽. Modem chip repair/replacement: 3,000–8,000 ₽. Oxidation cleansing: 1,000–2,000 ₽.
What can't be done:
- 🚫 Agree to a repair without a diagnosis ("we'll see along the way»).
- 🚫 Give the phone to a service where you do not give a check or contract.
- 🚫 Disassemble your phone yourself if you are not sure about your skills (risk of damaging plumes or fees).
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If the service offers to “switch” IMEI» 500 ₽ — They're either crooks or incompetent craftsmen. IMEI It requires deep knowledge and is often illegal (unless your phone is yours).