Installing a mobile operator card is the first and most important step after unpacking a new smartphone or switching to another provider. Owners of Xiaomi, Redmi and POCO devices often encounter a variety of tray designs, which can cause confusion for inexperienced users. Installing a chip incorrectly can lead to the device not seeing the network or, in the worst case, damage the contact area.
Modern models of the Chinese brand are equipped with hybrid slots that allow you to combine two SIM cards or one card and a microSD memory card. It is important to understand that the standard size of the chip today is Nano-SIM, which is much smaller than its predecessors. The installation process requires accuracy, proper positioning and the use of a special tool that comes with the kit.
In this guide, we will discuss in detail all the nuances of the procedure, from finding a hole to extract to software priority settings. SIM-shell-card MIUI You will learn how to determine the type of your tray, what to do if the phone does not see the network, and what hidden functions of managing two numbers exist.
Tool preparation and tray type determination
Before you start to physically affect the case of the smartphone, you need to prepare the workplace and tools. In the standard configuration of all Xiaomi devices is a special paper clip to remove the tray, but it is often lost or thrown away with the box. If the original key is not, you can use a thin needle, a paper clip or even an earring, but you need to act extremely carefully so as not to scratch the case or damage the mechanism.
A critical step is to visualize the end of the device, and there's a retrieval hole on the side, usually on the left or bottom, and there's often a schematic image next to it that indicates the type of tray. There are three basic configuration options in current models, and understanding the differences between them will prevent failure.
⚠️ Warning: Never use thick objects such as toothpicks or pins to retrieve the tray.The tree can crumble inside the mechanism, and too thick metal can jam the spring or damage the internal plumes, leading to costly repairs.
You can tell the type of slot by the marking on the tray itself, or by the number of contact areas, and if you see two card areas and one for memory, you have a full triple slot, and if the memory area shares space with the second SIM card, it's a hybrid option, requiring a choice between the second number and the expansion of memory.
Step-by-step installation process of Nano-SIM
Once you have decided on the type of tray and prepared the tool, you can go to the direct installation. Make sure that the smartphone is turned off, although modern devices support hot replacement, for the initial setting, it is better to turn off the gadget. Insert the tip of the clip into the hole next to the tray and press until the click, after which the mechanism will push the pad.
Remove the tray and place it on a flat surface with the contacts upwards. Notice the cut-out angle of the plastic frame, which corresponds to the shape of your body. SIM-If you have an old-format card (Mini or Micro), it should be replaced in the communication salon or carefully trimmed according to the template, although the latter option is not recommended due to the risk of damage to the chip.
☑️ Checklist of installation SIM-map
Place the Nano-SIM in the appropriate recess. It should lie perfectly flat, without protruding beyond the edge of the frame. If the card dangles or doesn't come in, you're trying to insert it with the wrong side or in the wrong slot. After installation, gently push the tray back into the case until it's fixed.
Special attention should be paid to the orientation of the chip. Most Xiaomi models should look down, but in some older or specific models (especially with a non-removable battery of the previous generation), the location may be different. Always check the icon on the tray itself, where the arrow indicates the direction of installation.
Features of hybrid slots and memory cards
Many budget and mid-budget smartphones Redmi and POCO They're equipped with hybrid slots, which means that the second compartment can be used for either the second compartment. SIM-It's either a microSD card, but not a microSD card, and users often have to choose between dual-SIM and embedded storage extensions.
If you plan to use two SIM cards, the memory card simply does not install in the second slot, in which case all media files, photos and applications will occupy the internal memory of the device, and if you are critically important storage, you can sacrifice the second number and install a flash card.
| Type of configuration | Slot 1 | Slot 2 | Opportunities |
|---|---|---|---|
| Two. SIM-map | Nano-SIM | Nano-SIM | Two-number operation, no memory card |
| SIM + Memory Card | Nano-SIM | microSD | One number, memory expansion to 512 GB |
| Triple slot | Nano-SIM | Nano-SIM + microSD | Two numbers and a memory card at the same time |
There is a common misconception that you can use adapters that allow you to insert both a memory card and a SIM card into a second slot at the same time. Such adapters exist, but they often have poor contact, can get stuck inside the phone or cause overheating. There is no official support for such solutions, and using them carries risks.
Can I use two memory cards?
Software configuration and management of two numbers
Once the cards are physically installed and the phone is turned on, the MIUI-enclosed Android operating system automatically recognizes the new chips. If that doesn't happen, check if the tray is sitting tight. If it is detected successfully, the operator's greeting will appear on the screen, and the signal icons will appear in the notification curtain.
For fine-tuning, go to the Settings menu → SIM-You can assign which card will be used for mobile data by default and which for voice calls, which is especially convenient if one tariff offers unlimited Internet and the other offers cheap minutes.
In the same section, you can set the network name settings, which makes it easy to distinguish between "Working" and "Personal" numbers, and you can also adjust the behavior of the phone when calling in: for example, always ask which card to call from, or use the last one you select.
⚠️ Note: When activating mobile data transmission on the second SIM-The first card can be temporarily switched to mode. 2G/3G or become inaccessible to voice communication if your phone does not support VoLTE or Dual technology 4G. Please provide support for these functions to your operator.
The app cloning feature deserves special attention, since in Xiaomi it allows you to run a second instance of a messenger (such as WhatsApp or Telegram) for a second SIM card, which eliminates the need to constantly rearrange cards or carry two phones.
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Use the "Help" function SIM-maps in settings to automate mobile internet switching in roaming or when the main network signal is weak.
Solution: The phone can't see SIM-map
When the phone is installed, it says, No. SIM-"Put in the cards" or "Put in" SIM-The first thing you can do is try to reboot the device. If that doesn't work, remove the tray and wipe the contacts of the card with a soft dry cloth. Finger fat or oxidation can disrupt the connection.
Check if the card is trimmed correctly. If you've been cutting down the size of the chip yourself, the edges might get bumpy, and the card doesn't fit tightly with the contacts, so you'd better go to the operator's salon for a free replacement with the right sized Nano-SIM.
The problem can also be a software failure of network modules: try resetting the network settings: go to Settings → Connection and Sharing → Reset Wi-Fi, mobile networks and Bluetooth. This action will return network settings to factory values, but will not delete your personal files.
- 📱 Make sure that SIM-card not blocked PIN-code (if you forgot the code, you will need to PUK).
- 📡 Check if the phone supports your carrier’s frequency (relevant to Chinese versions).
- 🔄 Try inserting the card into another phone to rule out chip failure.
- 🛠 If the card is running on another phone, your Xiaomi tray or antenna module may have malfunctioned.
In rare cases, a problem arises after a firmware update, in which case a complete reset or flashing of the device through the computer can help, but before resorting to radical measures, it is worth checking the status of the device lock.
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If SIM-The card is not detected in any slot and does not work in other phones, most likely, the chip is physically damaged and requires replacement from the carrier.
Security: PIN, PUK and data protection
Installation SIM-Cards are also a reason to think about the security of your room. By default, many operators do not require PIN-code when you turn on your phone, which makes your SIM vulnerable in case of device theft. PIN-code in security settings SIM-map.
Remember or write down. PUK-code that is issued with the card or available in the operator's personal account. PUK-More than 10 times the code is permanently blocked. SIM-A card that can only be recovered by re-releasing a new chip, an important protection against code selection by intruders.
Xiaomi also has a device protection feature that links your phone to your Mi Account, even if an attacker replaces your account. SIM-Your phone can lock or send you a notification about changing the number if this feature is activated in cloud services.
Check your call forwarding settings regularly. Sometimes viruses or fraudulent activities can redirect your calls and SMS to other numbers, which is especially dangerous for confirming banking transactions, these parameters are controlled through the call menu or USSD-request.