Modern smartphones from Xiaomi are famous for their functionality and affordable price, but beginners often ask about the correct installation of the communication module. the Redmi 8 model, released in 2019, received a hybrid slot, which requires care when mounting a map. Incorrect installation can lead to the fact that the device will not see the network or will work only one SIM. In this material, we will discuss the installation process in detail so that you can immediately start to use all the communication capabilities.
Before you start physically affecting the body of the gadget, you need to prepare the workplace and tools. You will need a special paper clip to remove the tray, which usually comes with the box, or a thin needle. It is also important to make sure that the smartphone is turned off, although many modern models support hot replacement, for the Redmi 8 it is better to be safe to avoid software failures. Preparing the correct size card is also a critical step, since inserting a reduced or damaged SIM is unacceptable.
Owners of this model often wonder which slot to choose for the main SIM card with a tariff for the Internet. The answer lies in the technical features of the hybrid tray, which we will talk about later. Understanding the architecture of the slots will help you avoid a situation where after installing two cards, memory card support disappears or one of the SIM cards works in 2G mode. Let’s look at the necessary tools and preparatory steps in more detail.
- 📌 Special paper clip for extracting the tray (or a thin needle with a blunt end).
- 📱 Xiaomi Redmi 8 smartphone with the screen off.
- 💳 SIM-Nano-SIM card (smallest size).
- 🧼 Soft fabric for cleaning contacts if necessary.
The first step in the installation process is to find a hole to remove the tray. On the Redmi 8, it is located on the bottom of the device, next to the USB Type-C connector and speaker. Be careful not to confuse the hole of the SIM card tray with the noise reduction microphone, which is on the opposite side of the case or next to it, but looks different. Pressure on the microphone can damage the sensitive membrane.
Insert a paper clip or needle into the hole and press with moderate force until a characteristic click. The tray should extend out of the body by a few millimeters, after which it can be carefully removed with your fingers. Don't use excessive force, since the spring mechanism is quite reliable, but the fragile plastic elements inside can break when you jerk. If the tray does not come out, check if you hit the hole correctly, and try to change the angle of the needle.
⚠️ Warning: Never use sharpened objects, such as stationery knives or sharp pins, to retrieve the tray.You may accidentally punctur the case and damage the battery or plumes located directly below the SIM card installation site.
Once you remove the tray, take a close look at its design. Redmi 8 uses a hybrid circuit, which means there are two card spaces, but they have different purposes. One slot is exclusively for Nano-SIM, and the second slot is a combined one: you can install either a second Nano-SIM or a microSD memory card. Simultaneously installing a second SIM and a memory card in one slot is technically impossible.
Notice the shape of the notches in the tray. They have roundings on one side only, which corresponds to the shape of the chip and the plastic base of the SIM card. Make sure that the golden contacts on the map point down to the contacts of the tray, and the bevelled corner of the map matches the bevelled angle of the seat. Wrong orientation will lead to the card simply not falling into the slots or, worse, the contacts will close.
Now that you've figured it out, you can start installing it. Put the tray on a flat surface and place the card in the appropriate notch. If you're using two SIM cards, the first one is usually installed in a slot marked with the number 1, and the second one is installed in a hybrid slot. The memory card has a separate compartment in the second position, unless you're using the second SIM.
Carefully press the card with your finger so that it sits level with the edges of the tray. The card should not protrude above the surface of the frame, otherwise, when inserted into the phone, it can get stuck or damage the side face of the case. Make sure the card lies tight and does not dangle. If you feel the backlash, it may be cropped incorrectly or has a non-standard thickness.
☑️ Pre-installing check
Once you've successfully put the cards in the tray, you need to put it back into the smartphone body. Hold the tray strictly horizontally, aligning its guides with the grooves in the case. Push the tray smoothly, without skewing. If you feel resistance, don't push it with force, it's probably skewed, and you need to take it out and re-insert it at the right angle.
When the tray is fully integrated, it has to be level with the phone's bezel and have no protrusions, and then you can turn on the device. The MIUI system on Redmi 8 automatically recognizes the new SIM cards and suggests that you adjust their settings, which usually takes a few seconds, and at the top of the screen, the signal level indicators appear.
What to do if the tray is not inserted to the end?
Importantly, Redmi 8 supports two SIM cards simultaneously, but with some limitations: Both slots support 4G networks, but high-speed Internet will only work on one of them, while the second will be switched to 2G or 3G mode for voice calls.
To manage SIM cards go to the Settings menu → SIM-Maps and mobile networks. Here you can choose which card will be used by default for calls, SMS And there's also a feature for switching SIM cards through the notification panel, which is very convenient for those who often change their communication priorities.
| Parameter | Slot 1 | Slot 2 (Hybrid) |
|---|---|---|
| Type of card | Nano-SIM | Nano-SIM or microSD |
| 4G support | Yes (main) | Yes (secondary) |
| Voice calls | Supported | Supported |
| Max, memory capacity. | - | up to 256GB |
If after installing the SIM card, the phone writes "No net" or "Unknown SIM card," don't panic. First, check the cleanliness of the contacts. Wipe the golden area of the SIM card with a soft dry cloth or a swallow. Oxidation or greasy spots from the fingers can prevent normal reading of data.
Also make sure that the settings do not include Air Mode. Sometimes the system may not correctly identify a new card if there were failures in the communication module before. Try to restart the device again. If the problem persists, check the health of the SIM card in another phone to prevent damage.
⚠️ Warning: Don't try to cut an old-format SIM card (Mini or Micro) to the size of a Nano unless you have a special cutter.Uneven edges of plastic can get stuck in the tray, and chip damage will cause the card to be completely inoperable.
One common problem is the conflict between the two operators: if both SIM cards are operating in ranges that the phone cannot handle at the same time, or if one of the cards is locked. PIN-It can be difficult to use code that you don't type when you download it. PIN-codes of their cards or disable their request in security settings.
In rare cases, the problem is software. Make sure your version of MIUI is updated to the latest available. The manufacturer regularly releases patches that fix errors in the modem and network protocols of different operators. You can check the update in Settings → About Phone → MIUI version.
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Use the adapter only as a last resort.Inserting the SIM card through a plastic adapter increases the thickness of the module, which can lead to a jamming tray inside the Redmi 8 case.
For users who are actively using mobile Internet, it is important to set up the access point (APN) correctly. Usually these settings come automatically with the first SMS from the operator, but sometimes they have to be prescribed manually. Incorrect APN settings are a common reason why 4G doesn't work even with a strong signal.
Go to your mobile network settings, select the SIM card you want, and find "APN" and click "New APT" and enter the data provided by your carrier. After saving, remember to activate that point by ticking next to it, which often solves problems with slow Internet.
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Proper installation of a SIM card is not only a physical hit in the tray, but also the correct software setting of priorities and access points for stable operation.