Smartphones series Redmi Note 9 from Xiaomi deservedly popular due to the excellent ratio of price and quality, as well as the support of two SIM-However, for many users, especially those who move from button phones or models with a fixed tray, the process of removing and installing communication modules may not seem obvious.
In this article, we will discuss in detail how to insert a second SIM into the Xiaomi Redmi Note 9 to avoid common errors. You will learn where the slot is, which side to place the chip, and how to set up a priority SIM card for calls and mobile Internet after installation. The correct sequence of actions ensures stable operation of the device.
It is important to note that the design of the tray in this model has its own features that distinguish it from older or, conversely, flagship versions of smartphones. Hybrid slot allows you to flexibly manage memory and number of active numbers, but requires careful installation. Below is a step-by-step instruction that will help you quickly activate the second number.
Preparation for installation and search for a slot
Before you start physically interacting with the device, make sure you have all the tools you need on hand. The Xiaomi Redmi Note 9 usually comes with a special paper clip to extract the tray, but if it is lost, a thin needle or stationery clip, straight to the desired diameter, will fit. The main requirement is that the tool must be thin enough to enter the hole, but strong enough to withstand the force.
Slot for SIM-cards in this model is located on the lower end of the body, to the left of the charging connector USB Type-C. Note that the tray is sealed and protected by a rubber seal, which provides spatter protection as standard. IP53. This means that you should not try to tamper with nails or a knife, as you can damage the moisture protection or scratch the frame of the smartphone.
⚠️ Note: Before removing the tray, we strongly advise you to completely turn off the smartphone. Although modern devices support hot replacement, the risk of short circuit contacts or software failure in determining the network when power is turned on still exists, especially when using non-original cards.
Find a small circular hole next to the elongated tray. Carefully insert the tool perpendicular to the body until the characteristic click. The mechanism will push the tray outwards, after which it can be removed with your fingers. Don't put too much effort: if the tray does not come out, try to slightly change the angle of the tool.
Tray layout and orientation SIM-map
The retrieved tray in the Redmi Note 9 has a specific shape designed to fit two nano-SIM cards and one microSD card at the same time, an important advantage of the model, since many competitors offer a hybrid slot where you have to choose between a second SIM and a memory extension. Visually, the tray is divided into two parts: one for a memory card, the other for two communication modules.
The hardest part for beginners is the correct orientation of the chip. There's always a schematic image on the tray showing how the card should lie. The gold pins of the chip should be pointed down to the smartphone board, and the cut corner of the card should match the shape of the notch in the tray. If you try to insert the card incorrectly, it just won't fall into the slots.
- 📱 SIM 1: The main location for your main SIM card is usually located closer to the edge of the tray or marked 1".
- 📞 SIM 2: The second seat for the additional number is often located next to the first or on the other side of the separator.
- 💾 MicroSD: A memory card slot that does not conflict with the second SIM, allowing all three elements to be used simultaneously.
Make sure that the cards fit tightly to the plastic base of the tray and do not protrude over its edges. If the memory card or SIM stick out, when the tray is closed, they can damage or damage contacts inside the phone.
Step-by-step installation instructions
The process of installing the second SIM in the Xiaomi Redmi Note 9 is technically simple, but requires care. Take the tray in your hands and position it so that you can see the marking. SIM-map to the appropriate slot, making sure that the cut angle matches the shape of the plastic. then set the second card to the adjacent slot, following the same orientation logic.
If you're also using a memory card to store photos and apps, put it in the storage compartment, and the contacts of the memory card should also look down. After you've placed all the items, you should just pin them down with your finger to lock them in the slots, and the tray should be assembled completely, without any gaps between the card and the plastic.
☑️ Checklist of correct installation
Now, take the smartphone in your hand and find the guides for the tray. Put the tray in the case with the same side that was taken out. Don't flip it over. Push the tray carefully inwards to the end. You should feel the light resistance of the spring, and then click, which means that the mechanism has fixed and leveled with the body.
After installation, turn on the device. MIUI It will automatically detect new modules, if the SIM card has not been used in this phone before or is protected. PIN-In the code, you'll see a request to unlock on the screen. Enter the code provided by the operator to activate the communication.
Setting up two SIM-card MIUI
Once you have successfully installed and turned on your smartphone, you need to set up the software correctly. Android’s MIUI-enabled operating system provides flexible tools for managing two numbers. By default, the phone can assign one of the SIMs to priority for all activities, which is not always convenient.
To set up, go to the Settings menu and select the item SIM-maps and mobile networks. Here you'll see a list of installed maps: SIM 1 and SIM 2.You can rename them for convenience, for example, "Worker" and "Personal", or "MegaFon" and"Tele2", This is especially useful if you don't have colored marks on the maps themselves.
| Parameter | Description of settings | Recommendation |
|---|---|---|
| Default calls | Selecting SIM for Outgoing Calls | It is better to put “Always ask” to choose the number before each call. |
| Mobile Internet | Data transfer simplification (4G/LTE) | Choose the tariff with the largest packet of traffic or unlimited. |
| SMS default | Primary number for messages | Specify the SIM that most often receives confirmation codes. |
| 4G settings | Network mode | It is recommended to use “preferably LTE” for high speed. |
Special attention should be paid to roaming settings and network type. If you are traveling, make sure that the second SIM (if it is local or tourist) is on mode, and in this menu you can limit the use of mobile Internet for certain applications, which will help save traffic to the main SIM.
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Use the Traffic Limit feature in the second SIM settings, if it is a guest card with a small megabyte package, to avoid unexpected expenses.
Solution: If the second sim doesn't work
Sometimes, after installation, users are faced with a situation where the phone sees only one card or the second SIM is displayed as "No net." The first reason may be a loose attachment of the card in the tray. Try to remove the tray again and wipe the contacts of the SIMKA soft dry cloth to remove possible oxide or dust.
The second common problem is format incompatibility. Redmi Note 9 works exclusively with nano-SIM cards. If you use an adapter (a micro or standard SIM adapter), contact can be unstable.
⚠️ Warning: Never cut off the old one SIM-You can use scissors to fit it into a nano-sized map, you can damage the chip or you can disrupt the geometry of the map, which will lead to a tray getting stuck inside the smartphone.
If the cards are physically OK, check the software settings. Make sure the second SIM slot is activated in the settings menu. Sometimes after the system update, the switch may get lost. It's also worth checking if the "Airplane" mode is set specifically for the second slot in the quick notification curtain settings.
What to do if your phone is writing"SIM-map not installed"?
Use of hybrid mode and memory card
Although the Xiaomi Redmi Note 9 features a full-fledged triple slot, users are often interested in the nuances of working with large amounts of data. Supported memory cards up to 512 GB (officially) and often more in practice. With two Sims and a memory card running simultaneously, the load on the power controller increases, which theoretically can slightly affect autonomy.
It's important to format the memory card correctly after installation, and the system will suggest using it as "Portable Storage" or "Internal Storage." The first option allows you to transfer the card to other devices without losing data, the second option is to link it to the phone, encrypting data. For most users, the first option is the best option.
When actively recording video in high resolution (4K), it is recommended to use memory cards with a high speed class (U3, V30 and above), otherwise the recording may be interrupted or go jerky, especially if there is an active data exchange through the second SIM card in parallel.
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The Redmi Note 9 triple slot allows you to choose between communication and memory, but requires quality microSD cards to avoid reading errors.