Buying a new smartphone is always a pleasant thrill, especially when you have a fresh device from Xiaomi or Redmi. However, the first thing that a user faces after turning on the device is the need to start communication. Often the process seems obvious, but modern shells MIUI and HyperOS have their own nuances that can confuse even an experienced owner of gadgets. Installation or ignoring system requests can lead to the fact that the network will never appear.
In this article, we will take a closer look at how to properly activate a SIM card on Xiaomi devices to avoid typical errors. We will look at the physical aspects of installing a chip, network software settings, and solving common operator definition problems. Understanding these processes will save you time and nerves on your first run.
It's worth noting that the procedure may vary slightly depending on the operating system version and the smartphone model, but the basic principles of working with the communication module remain the same for the entire model range of the brand.
Preparation for installation and compatibility check
Before you extract the tray, you need to make sure that your device supports your operator’s frequency ranges.Modern Xiaomi smartphones are generally versatile, but when buying devices designed for other markets (such as the Chinese versions of Global ROM), nuances can arise with support for certain 4G and 5G. Checking the specifications on the official website or in the instructions is an important first step.
It's also critical to assess the physical condition of the SIM card itself. If you're using an old chip that went from one phone to another, its contacts could have oxidized or micro-scratches. Golden contacts should be clean and shiny. If you see dirt on the surface, gently wipe them with a soft cloth without pile, but do not use aggressive chemical solvents.
Particular attention should be paid to form factor.The Nano-SIM standard is dominant, and trying to insert a larger card, even trimmed with scissors, can lead to a tray getting stuck or damage to the reader.If your SIM card doesn't fit in size, it's better to contact the communications salon for a free replacement than risk the integrity of the smartphone.
⚠️ Warning: Never force a tray into the nest. If it doesn't come in easily, you're either misdirecting it or using an incorrect format SIM card. Excessive effort can break the internal contacts.
Make sure the smartphone is turned off before you start manipulating. Although Hot-Swap technology allows you to change the cards on the device on, when you first activate or after resetting, the system may not correctly recognize the new chip without restarting.
Physical installation of SIM card in the tray
The process of extracting the tray on Xiaomi smartphones is standardized, but requires care. This uses a special metal clip that comes with the kit, or a similar thin tool. It is important to enter it strictly perpendicular to the hole located on the end of the device. Usually, next to the hole there is a small icon indicating which slot is intended for the SIM card and which is only for the memory card.
Most modern Xiaomi models use a combined tray or two separate SIM card slots. If you have a hybrid slot model, using a second SIM card eliminates the possibility of installing a microSD memory card. Carefully inspect the tray: often it has a schematic image showing how to position the chip correctly. The bevelled corner of the SIM card should match the beveled angle in the tray.
Once you've placed the card in the tray, make sure it's flat and doesn't protrude beyond the edges. Even a minimal skew can cause the tray to not enter the end and the contacts to close. Put the tray back into the case until the characteristic click. If there's no click, maybe you're inserting the tray on the wrong side, flip it over.
☑️ Control of SIM card installation
Once you have the physical setup, you can turn on the device, and at that point, the phone will start to question the modules that you have installed, and if you're using a dual-sim device, the system will immediately detect the presence of two chips and suggest basic settings for each chip, and don't ignore those requests, because they form the primary network profile.
Primary network setup in MIUI and HyperOS
Once the operating system is loaded, if the SIM card is active and defined, signal level indicators will appear at the top of the screen. However, to fully work, you often need to manually activate the settings menu. Go to Settings, then select a paragraph. SIM-maps and mobile networks. This shows all the maps installed.
In the menu that opens, you'll see a list of your SIM cards. Make sure the switch opposite the card is activated. If the slider is turned off, the phone won't try to log in to the operator's network, which saves battery power but blocks communication. For the main card, through which calls and mobile Internet will go, it's recommended to immediately prioritize.
An important step is to set up the preferred network type. In the Preferred Network Type menu, select the value Preferably LTE or 5G preferably if your operator and tariff support these standards. Automation usually works correctly, but in areas of unstable coverage, manual selection can improve connection stability.
💡
If you travel frequently between regions, leave the network mode automatic.Forcing to switch to 4G/LTE in areas where there is only 2G/3G will result in a complete loss of communication.
APN hotspots are also worth a special attention. 95% of the time, modern Xiaomi smartphones automatically load the correct settings when a SIM card is first detected. However, if the Internet is not working and calls are passing, you may need to manually register the parameters, which can be found on your carrier's website or obtained by automatic message.
Solving problems with the definition of the SIM card
A phone that says "Sim card not found" or "no service" can happen for a variety of reasons. First of all, try rebooting your device. This simple action helps to reset the temporary errors of a radio module that might have "hang" when trying to log in. If the reboot did not help, move on to a deeper diagnosis.
Check if the SIM card is blocked. PIN-When you turn on the phone, the system can request input. PIN. If you enter the wrong code three times, the card will be blocked and you will need to enter the wrong code. PUK-code. PUK-The code also has a limit of attempts, after which the SIM card will be permanently blocked and will require replacement.
Sometimes the problem is that the shell itself is software-based, so try to extract the SIM card, erase the contacts (very carefully) and paste back in, and it makes sense to check the SIM card on another phone, and if it works on another device, it means that the problem is in the slot or your Xiaomi software.
| Symptoms. | Possible cause | Method of decision |
|---|---|---|
| Demands. PIN-code | Card protection | Enter the correct code or PUK |
| No net (cross) | Radio module failure | Reset or flight mode |
| Can't see the SIM card. | Bad contact. | Cleaning contacts, reinstallation |
| Only emergency. | Blocking by the operator | Balance and status check |
⚠️ Warning: If the phone suddenly stops seeing the SIM card after falling or getting moisture, don't try to charge the device. moisture inside the housing can cause the antenna module to short circuit.
In rare cases, network resets help. This operation will not delete your personal files or applications, but will return all network settings (Wi-Fi passwords, Bluetooth and mobile network settings) to factory values. You can find this option by using the Settings path → Connection and Sharing → Reset Wi-Fi, mobile networks and Bluetooth.
Setup of two SIM cards and the Internet
Xiaomi smartphone owners often use two SIM cards at the same time. The MIUI shell provides flexible tools to manage them. In the SIM management menu, you can assign which one will be used for default voice calls and which for mobile Internet. This separation allows you to optimize costs using tariffs from different operators.
The "Use Mobile Internet" feature allows you to select one of the cards to transfer data. If you are actively using the Internet on the first card, the second card can temporarily lose the network during a call if VoLTE is not enabled.
For comfortable use of two numbers, it is recommended to configure individual melodies and signatures for each SIM card, this will help you immediately understand which number is coming from a call or message, and you can also limit the background data transfer for the second SIM card to save battery power.
What is VoLTE and how to turn it on?
If you are actively using number-bound messengers, make sure that each SIM card has the correct access point set up. Sometimes when you switch the main SIM card for the Internet, messages from the second card may come with a delay due to the switching of the radio module between frequencies.
Activation of eSIM on Xiaomi devices
Xiaomi’s current flagship models are increasingly supporting eSIM technology, an embedded SIM card that allows you to activate your data plan without having to physically insert a plastic chip. The eSIM activation process is fully software-based and requires a stable Wi-Fi connection.
You will need to activate it. QR-In the phone settings, select Add a tariff plan in the mobile network section. The camera scans the code and the operator profile is loaded into the secure device module. This method is particularly convenient for travelers, allowing you to quickly connect local operators.
Multiple eSIM profiles can be saved on a single device, but one is usually active at the same time unless a physical card hybrid mode is used.Switching between profiles takes a few seconds and does not require a phone reboot.
💡
eSIM technology eliminates the physical wear and tear of contacts and the risk of losing a miniature SIM card, making the process of changing the operator a matter of several clicks.
It is worth considering that when resetting the phone to factory settings, eSIM profiles can be deleted depending on the type of reset chosen. QR-code from the operator or the ability to retrieve it through the personal account, so as not to be left without communication after formatting.