The situation when a modern smartphone Xiaomi suddenly stops seeing the SIM card, causes panic, especially if there is no Wi-Fi on hand to communicate. SIM-"Maps" that renders the device useless for calls and mobile Internet, most often the problem is not hardware failure, but software failure or incorrect contact.
Before you carry the gadget to the service center, you need to conduct a number of diagnostic actions that will help to localize the source of the malfunction. owners of Redmi and POCO often face software conflicts after the updates to the MIUI or HyperOS system. It is important to consistently exclude external factors, such as damage to the operator’s plastic card itself or contamination of the tray contacts.
In this article, we will discuss all possible causes, from banal dust in the slot to complex errors of the base station, you will learn how to clean contacts, reset network settings and what to do if IMEI is lost. 80% of the time the problem is solved by software resetting network settings or replacing the SIM card with a new one from the operator.
Primary diagnosis and physical condition check
The first thing you need to do is make sure that the problem isn't caused by mechanical damage or a banal lack of contact. Remove the SIM card tray and inspect it carefully. Often, the cause of failure is oxidation of the contacts or a microscopic layer of fat that gets onto the chip when you install it.
Gently wipe the golden contacts of the SIM card with a soft cloth without a pile, slightly moistened with alcohol. Make sure that the chip does not have scratches or chips. If you have the opportunity, install the SIM card in another phone, this will allow you to determine exactly whether the communication module itself in the smartphone is to blame or the problem on the operator's side.
- 🔍 Inspect the tray for distortion or deformation of contacts inside the slot.
- 💨 Gently rinse the SIM card slot with compressed air to remove dust.
- 🔄 Try installing the SIM card in the second slot if your Xiaomi supports Dual SIM.
- 📏 Make sure the size of the card (nano, micro, standard) matches the tray and does not require trimming.
If the physical condition of the card and tray is not a question, but the phone still does not see the SIM, move to software methods of solving. Sometimes it helps to simply restart the device, which resets temporary errors of the communication module.
⚠️ Warning: Never try to remove or insert a SIM card tray while the phone is on if there is an active data record or system update at this point, although modern Android smartphones support a “hot” replacement, the risk of software driver failures persists.
☑️ Diagnostics of physical fitness
Software resetting network settings and rebooting
The most effective way to resolve modem driver software conflicts is to reset network settings, which returns connection settings to factory values, removing erroneous APN configurations and network preferences that may have accumulated over time.
To do this, go to your device's settings menu. The path may vary slightly depending on the version of the MIUI shell or HyperOS, but the logic remains the same. Find the connection section and select the reset option.
Once the reset is done, the phone will automatically restart. That's normal system behavior. PIN-SIM card code (if installed) and check for network icons.
What exactly is removed when the network is reset?
It is important to note that this procedure does not affect your personal files, photos or installed applications; it affects only the communication modules of the smartphone.
- 📱 Go to Settings. → Connection and sharing → Reset Wi-Fi, mobile networks and Bluetooth.
- 🔘 Click the Reset button at the bottom of the screen and confirm the action.
- 🔌 Wait for the automatic reboot of the device.
Configure APN access points for operators
A common reason why a smartphone sees the network but does not have access to the Internet or is unstable is the wrong settings of APN access points. Communication operators periodically change settings, and automatic settings updates may not work correctly.
You need to manually check and, if necessary, create a new access point. Go to the mobile network settings and select your SIM card. Find the access point (APN) item.
If the list is empty or the current point is not working, create a new one by entering data relevant to your region and operator. Usually, just enter the name and access point, the rest of the parameters will be substituted by the system itself.
| Operator. | Access Point (APN) | Type of authorization |
|---|---|---|
| MTS | internet.mts.ru | PAP or CHAP |
| Beeline | internet.beeline.ru | Not required |
| MegaFon | internet | PAP or CHAP |
| Tele2 | internet.tele2.ru | PAP or CHAP |
Once you have entered, be sure to save the profile and activate it by ticking it. Reboot your phone to apply the changes. In some cases, you need to switch network mode.
Problems with IMEI and database recovery
One of the most serious problems is the loss of the IMEI identifier. If the device status instead of numbers displays zeros or dashboards, and the task manager sees the mdmd process or modem errors, then the program part responsible for communication has flown.
You can check the IMEI by typing *#06# in the phone. If the number doesn't display or isn't displayed correctly, standard reset methods may not help, often after a failed firmware or root-right experiment.
Owners of devices with MediaTek or Qualcomm processors can try to restore IMEI through the engineering menu, but this requires caution. For ordinary users, the safest way is to flash stock software through the computer.
- 🔢 Dial *#06# to check the display IMEI.
- 🛠 Use the Mi Flash Tool to install clean firmware.
- 📉 Avoid installing custom recavers if you are not sure of compatibility.
- 💾 Save a backup copy of the section EFS before any manipulation.
⚠️ Attention: Change or substitution IMEI Android devices are illegal in many countries and can result in a device being blocked by a database operator.
Conflicts after the MIUI/HyperOS system update
An operating system update is always a lottery. A new version of the MIUI or HyperOS shell may contain bugs that conflict with your specific region's radio module. Often users notice that after an update, the phone begins to "lose" the network.
In such cases, cleaning the cache of the Phone app and system services helps. Go to the application settings, find the system processes associated with communication, and clean their data. It is also worth checking whether the traffic saving feature is activated, which can block the background operation of the SIM card.
If the problem appears immediately after the update, it makes sense to roll back to the previous version of the software or wait for a patch from the developers. In the developer settings, you can try to switch your preferred network type.
Sometimes it helps to reset your settings to factory, but this is a last resort. Before you do that, make sure that all the important data is stored in the cloud. Statistics show that one in five network failures after an update is eliminated by a complete reset.
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If the problem appeared strictly after the system update, the most likely cause is a software conflict of the new version of MIUI with modem drivers.
Hardware malfunctions and communication module
When software methods are exhausted, we have to talk about hardware. In Xiaomi smartphones, especially in models with a metal body or after falls, the antenna plume or the communication module itself can depart.
It is also possible to fail the power controller, which is responsible for supplying voltage to the SIM card slot, and if the phone fell or came into contact with water, the probability of hardware failure is up to 90%.
Diagnostics at home are limited. You can gently tap your finger on the back cover in the area of the camera (where the modem is often located), but this is a temporary solution. It requires disassembly and multimeter testing.
- 🔨 Check if there have been any bumps or falls in the device.
- 💧 Look at the moisture indicators (LCI) inside the sim card tray.
- 🔌 Try gently pressing the area of the camera module when the phone is on.
- 🏥 Contact the service if the device is under warranty.
⚠️ Warning: Self-disassembly of the Xiaomi smartphone, which is under warranty, will lead to the loss of warranty obligations.
In conclusion, if none of the software methods worked, and the SIM card is good in other phones, it is a hardware malfunction. In most cases, replacing the plume or soldering the connector solves the problem.