Modern smartphones of the Poco brand, which is a sub-brand of Xiaomi, are famous for their excellent price-performance ratio. The Poco X3 model (including the NFC and Pro versions) has become a real hit, but new owners often have a question about the correct installation of the operator card. Wrong actions when removing the tray can damage the case or the slot itself, so it is important to know the nuances of the design.
Unlike the older models, where the battery was removable, it uses a combined slot, which means you can install two nano-SIMs or one SIM card along with a microSD card. It is important to follow the sequence of actions to avoid bending contacts and ensure stable reception of the signal in the future.
In this article, we will discuss in detail the process of preparing, retrieving the tray, installing the chips and initial network configuration, and we will focus not only on the mechanical part, but also on the software settings that are necessary for the correct communication in the Android operating system with the MIUI shell or HyperOS.
Preparation of the workplace and necessary tools
Before you start physically affecting your smartphone, you need to prepare your workplace, and the ideal table is one that has good lighting and a flat, clean surface, and small parts like a tray or a paper clip are very easy to drop and lose when you act on weight or on a carpet.
The main tool for you will be a special metal clip that comes with the device, it has a special shape that allows you to safely press the extraction mechanism. It is strongly recommended not to use sharp objects such as needles, pins or scissors, as they can easily damage the locking mechanism or scratch the body.
⚠️ Warning: Before any manipulation of the slot SIM-While current standards support hot replacement, power cuts ensure that the system correctly recognizes the new chip when it starts and eliminates the risk of short circuits.
Also, you should prepare the operator's plastic card in advance, make sure it has the Nano-SIM format, which is the smallest of the existing ones, and if your card is larger, use an adapter or contact the communications salon to replace it with the correct format.
☑️ Preparation for SIM card installation
Location of the tray and the process of its extraction
In the Poco X3, the SIM card tray is located on the top end of the case, which is standard for many Xiaomi devices, but it is important not to confuse it with an infrared port or microphones, which can also be on the top edge.
Look carefully at the end of the device, and you'll see an oblong oval element that protrudes slightly or is level with the frame, and next to it there should be a small circular hole, and that's where you put the tool, and in some versions, there may be a barely noticeable SIM card icon next to the hole.
Take a paper clip and insert its sharp end into the hole perpendicular to the body, press it confidently, but without excessive effort. You should feel a slight click of the spring mechanism, after which the tray will slightly extend outwards, and then you can carefully remove it with your fingers.
- 📍 Find the top end of the smartphone, where the oval tray is located.
- 📍 Insert the paper clip into a small hole next to the tray strictly perpendicular.
- 📍 Press until the characteristic click and remove the platform with your fingers.
- 📍 Pay attention to the scheme squeezed on the tray itself, it will tell you where to put the SIM, and where the memory card is.
If the tray doesn't extend when you press it, don't use force. Check if the paper clip is evenly worth it. Sometimes the mechanism can get jammed because of the dust, but in new devices this is rare. The main thing is not to pick the tray crack with sharp objects, trying to smack it.
Orientation of chips and installation in a combined slot
The retrieved tray in the Poco X3 is a specific shape, a single platform with two recesses, one for a microSD card and the other (or two, depending on the regional version) for a SIM card. It is important not to confuse the sides when installing.
Look at the cutout in the tray. It's completely the same as the circuit of the chip. Set the Nano-SIM so that the golden contacts are pointing downwards to the inside of the tray. The cut corner of the card should match the bevel in the plastic frame of the tray. The map should be tight and not wobbly.
What to do if the SIM card is not held in the tray?
If you plan to use two SIM cards, make sure both are nano format.Installing a larger (micro or mini) card even with cropped edges can cause the mechanism inside the phone to jam, as the thickness of the plastic may vary.
For a microSD card, the principle is the same: contacts down, bevelled corners on the circuit. However, remember that in a combined slot, you often can not use a second SIM card and a memory card at the same time. Usually either a 1 + slot 2 for sims, or a slot 2 is freed for flash memory.
| Component | Format | Orientation of contacts | Maximum volume |
|---|---|---|---|
| SIM-map | Nano-SIM | Down (to the tray) | Standard of operator |
| SIM-map | Nano-SIM | Down (to the tray) | Standard of operator |
| Memory map | microSD | Down (to the tray) | up to 1 TB (officially) |
Inserting the tray back into the smartphone case
Once the cards are placed in their cells, you have to put the tray back in place, which is a critical step, because the wrong insert can break the contacts inside the phone, and the tray has only one correct position to return.
Take the tray by the edges and hold it to the hole in the end of the smartphone. Notice the bevels and the shape of the frame. It should come in easily, without resistance. If you feel a push, don't push. Take out the tray, flip it 180 degrees and try again.
When the tray enters the body about halfway or to the characteristic stop, gently press your finger on it until completely snapped. It must stand level with the frame of the body. No parts of the tray should protrude outside, otherwise the leakage (if declared) and aesthetics of the device will be violated.
⚠️ Warning: Never insert a tray unless it contains a SIM card or memory card. An empty tray can fall deeper than it should or damage the contact groups inside the slot, as nothing will serve as a strut.
Once you make sure the tray is firmly set, you can proceed to turn on the device. Visually check that the cards are set correctly by looking at them in good light before inserting. Golden contacts should not be scratched or contaminated.
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Wipe the golden contacts of the SIM card with dry soft cloth before installation. Fat marks from the fingers can oxidize over time and degrade the quality of the network signal.
Initial network setup and selection SIM-map
After the smartphone is turned on, Android will automatically detect the communication modules installed, a welcome message from the operator or a request to set up a new SIM card will appear on the screen. If this does not happen, check the status at the top of the screen.
To manage two SIM cards, the Xiaomi Poco X3 has a user-friendly interface: you need to choose which card will be used for mobile Internet and which for voice calls by default, which is especially important for saving traffic if the rates on the SIM cards differ.
To get into the settings, go to the Settings menu, then select the item SIM-And you can see here a list of all the maps that you've detected, and if you click on a particular SIM card, you can set the parameters in detail: 4G, Set up an access point or change the network name.
- 🌐 Select a SIM card for data transfer in the item "Internet".
- 📞 Assign a basic SIM card for outgoing calls.
- 💬 Set your preferred card to send SMS-message.
- 🔄 Activate Repeat Choice if you want your phone to ask for a SIM card every time you call.
You can also include HD Voice or VoLTE in this menu if your carrier supports this technology, which allows you to have high-quality conversations while using the Internet without switching to 2G/3G.
Solution: if the SIM card is not determined
Sometimes, after you install the card and turn on the phone, the status bar may have a crossed-out SIM card icon or a sign saying "No service." This does not always mean a breakdown. Often the problem lies in a software failure or contamination of contacts.
First, try rebooting your device. This is a trivial action that helps 80 percent of the time, because modem re-initiates the network search, and if the reboot doesn't work, remove the tray and wipe the SIM card contacts with a soft wipe or an alcohol wipe.
Check if the SIM card itself is active, insert it into another phone to make sure it is working and not locked by the operator, and also make sure that the phone settings do not turn on the "On-Air" mode, which completely disables all wireless modules.
⚠️ Note: If the phone says "Unknown" SIM" require PUK-code, don't enter the wrong codes repeatedly. PUK-The code will lead to a complete blocking of the SIM card, which can be restored only in the office of the operator with a passport.
In rare cases, the problem may be software. Make sure your version of MIUI is updated to the latest available. Operators often change the settings of access points, and old profiles may not work correctly.
Optimization of two SIM cards in MIUI
Poco X3 owners often use two different carrier SIM cards for better coverage. The MIUI shell allows for flexible customization of use cases, such as setting up automatic switching to the card with the best signal when calling.
The SIM control menu has a traffic control feature, so you can set a limit for each SIM card separately, and when the limit is exhausted, the mobile Internet on this card will automatically shut down, saving you from unexpected expenses.
Also pay attention to roaming settings.If you are traveling, make sure that data roaming is enabled for the second SIM card (which may be local), otherwise the internet will not work even if the fare allows.
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Proper installation of a SIM card is not only a mechanical action, but also a competent software setting of priorities to save budget and improve communication.