Xiaomi smartphones are well-deservedly popular for their excellent value for money, and the Redmi 4A has become a hit in its segment. However, despite the simplicity of the device, new users often have difficulties with initial installation of communication modules, especially given the specific design of the tray. Incorrectly installing the chip can lead to the fact that the phone will not see the network or, in the worst case, will be damaged connector.
In this article, we will discuss in detail how to properly remove the tray, determine the orientation of the chip and activate the second communication line without contacting the service center. You will learn about the nuances of working with a hybrid slot and understand why the phone sometimes does not read operators even after the correct physical installation.
You don't need complex hardware to get started, you just need to be mindful and have a basic understanding of your gadget's device, and we'll look at everything from finding a paper clip to checking the signal level in the MIUI settings.
Preparation of the workplace and necessary tools
Before you start mechanically affecting the body of the smartphone, you need to provide a comfortable environment for work. The ideal option is a table with good lighting, where you do not lose small parts. You will need a special metal clip to remove the tray, which usually comes with the device, or a thin sewing needle.
It is strongly recommended not to use thick pins or knives, as they can easily damage the latch mechanism or scratch the body. Also make sure that your hands are dry and clean, so as not to leave traces of fat on the contacts or screen.
⚠️ Warning: Before any manipulation of the tray SIM-While current standards support hot replacement, power cuts eliminate the risk of short circuits and software failures in identifying a new operator.
If the paper clip is lost, you can carefully use the thin tip of the stationery scissors, but act with the utmost care. The main requirement for the tool is that it must be thin and durable to enter the small hole effortlessly.
☑️ Preparation for installation SIM
Tray design and types SIM-map 4A
Model Redmi 4A It's equipped with a combined slot, which is often confusing for users. It's an oblong tray and two chip indentations, but they're not equivalent. SIM-Nano-SIM card format, which is the smallest to date.
The second socket is hybrid, which means you can use it in two ways: either to put a second socket in. SIM-The same Nano-SIM card format, or microSD card. Simultaneous installation of the second SIM and memory card in this slot is technically impossible, as they occupy the same physical space.
- 📱 Slot 1: Nano-SIM only (main SIM card).
- 💾 Slot 2: Hybrid (Nano-SIM second or microSD up to 128 GB).
- 🔌 Form factor: Nano-SIM (12.3 × 8.8 mm).
It is important to understand that if you plan to use two SIM cards, then expanding the memory of the device with a microSD card will not work without using cloud services or using a microSD card. OTG-If you're more interested in memory, you'd better give the second slot to the storage.
What to do if SIM-map larger than Nano?
Step-by-step: how to insert a SIM card
The process of installing the communication module requires care, but it does not take much time. First, find a small hole on the bottom end of the smartphone next to the tray frame. Insert the prepared paper clip perpendicular to the body and slightly press until a characteristic click. The tray should be extended a few millimeters, after which it can be removed with your fingers.
Place the extracted frame on a flat surface and inspect it carefully. You will see cutouts that repeat the outlines of the Nano-SIM. Set the chip in the appropriate socket so that the cut corner matches the shape of the cutout. Contacts (the golden part) should look down, to the phone screen when you insert the tray back, or up, if you look at the tray itself in your hands - it is important not to confuse the sides here.
| Element | Action. | Checkpoint |
|---|---|---|
| Tool. | Put the paper clip in the hole | A slight click is heard |
| Orientation | Put the chip in a frame. | The angle is the same. |
| Contacts | Check the direction | Gold contacts look down |
| Installation | Put the tray in the phone | The tray enters before the click without effort |
After you put the chip in, gently insert the tray back into the phone, it should come in smoothly, without using excessive force. If you feel resistance, stop and check the tray's orientation correctly, you can't turn it over. Bring the frame to the end to a light fix.
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If the tray is not inserted to the end, do not push it. SIM-The card does not extend beyond the plastic frame and lies exactly in the recess.
Setting up two SIM-card-card MIUI
Once the smartphone is turned on, MIUI will automatically detect the modules installed. If two cards are inserted, the phone will suggest setting up their use, you will be asked to assign names to the SIM cards (for example, "Work" and "Personal") and select color labels for easy identification in the interface.
In the settings menu, which can be called through Settings → SIM-maps and mobile networks, flexible traffic and voice management, you can assign one card to the Internet by default, and use the other only for calls, which saves money on different tariff plans.
Particular attention should be paid to the item "Mode of the 2G/3G/4G". For the main SIM card through which you access the network, it is recommended to select the mode Preferably LTE. For the second card, if it is used only for calls, you can leave an automatic selection or forcefully put 2G/3G, to save battery life, as a constant search for the network 4G on the second line, you're using up energy.
Possible problems and methods of solving them
Sometimes, after installation, the phone says, “No.” SIM-"Cards" or "Emergency Calls Only." First, check if the contacts are contaminated. Rub the gold surface of the chip with a soft dry cloth or eraser to remove oxides or dust that may interfere with contact.
Another common reason is frequency incompatibility or IMEI locking. Make sure your phone is not locked to a specific operator (most often with devices imported from abroad). Also check if the SIM card itself is activated - new numbers sometimes require activation through a call to the operator.
⚠️ Warning: If the phone suddenly stops seeing the SIM card after falling or getting moisture, do not try to dry it with a hair dryer or put it on the battery.In this case, there is a high risk of damage to the power controller, and the device requires professional diagnosis.
A software failure can also be the culprit. Try resetting your network settings to factory settings. Go to Settings → Advanced Settings → Restore and Reset → Reset your Wi-Fi, mobile internet and Bluetooth settings. This action will not delete your personal data, but will return the network configurations to their original state.
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In 90% of cases, the problem of “no network” is solved by simply restarting the device or re-installing it. SIM-contact-cleaning cards.