Modern Xiaomi, Redmi and POCO smartphones are equipped with compact slots that require careful handling. Many users for the first time face difficulties in the initial configuration of the device when you need to activate communication. Wrong actions can damage the tray or the card itself, so it is important to know the exact algorithm of actions.
In this article, we will take a closer look at the process of installing a communication module, from finding the right tool to checking the signal. Your data security and integrity depend on following simple rules. We will look at the nuances for different models, including devices with combined slots and support for memory cards.
Before you start physically affecting the gadget, make sure it's turned off. Although most current models support hot replacement, it's best to completely reboot the device for initial installation and network setup, allowing the system to correctly recognize the new operator and automatically adjust Internet access settings.
Tool preparation and tray inspection
The first step is to find a special key to remove the tray, which is usually bundled with the device and is a small metal clip. If the original tool is lost, you can use a regular stationery clip by unbending it, or a thin needle, the main requirement is that the tool must be strong enough and thin enough to enter the hole, but not damage the internal mechanisms.
In modern Xiaomi models, the slot is most often located on the bottom edge, next to the USB Type-C charging connector or microphone. However, in some older or specific versions, it can be on the upper or side edge. The tray is a thin metal or plastic frame with a notch under the card.
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Use only metal tools to extract the tray.Plastic toothpicks can break inside the hole, requiring the phone to be disassembled at a service center.
Make sure your hands are dry and clean, and fatty traces or moisture can get inside the case through a clip opening, which is not desirable for electronics. SIM-The card, making sure it has the right format - usually Nano-SIM, the smallest standard to date.
The process of extracting the tray and installing the map
Find a small circular hole on the case next to the long slot of the tray. Put the tip of the key perpendicular to the surface of the case. Don't push with all your strength; press it with enough confidence but moderate pressure. You will feel a slight click, and the tray will move out a few millimeters, after which it can be carefully pulled out with your fingers.
Put the extracted tray on a flat surface. Notice its shape: one corner is always bent. This is not accidental, but done to prevent improper installation. Nano-SIM format is the standard for all current Xiaomi smartphones released after 2016. If you have a larger card (Micro or Mini), you should contact the operator's salon to replace it or carefully trim the outline using a special stencil.
☑️ Pre-installing check
Place the card in the notch tray so that the bevelled angle coincides with the notch in the frame. Golden contacts should look down to the smartphone screen if you hold the phone with the screen to yourself, or up, if you look at the tray separately, navigate by the pictogram on the tray itself. The map should lie tight, not wobbly or protrude beyond the edge of the frame.
⚠️ Note: Never put a tray in your phone without SIM-cards if the instructions for your model indicate that this may damage the contact areas inside the slot.
Features of hybrid slots and two SIMs
Many Redmi models and POCO They're equipped with a hybrid slot, which means you can use either of these. SIM-card SIM-card and one microSD card. simultaneously install two SIMs and a flash card in such devices is technically impossible.
The design of a hybrid tray usually involves two cells. The first cell (SIM 1) is designed strictly for the operator's card. The second cell can receive either a second SIM card (SIM 2) or a memory expansion card. When installing two communication cards, make sure that they are both correctly oriented according to the circuit on the tray.
What to do if you need a second number and a memory card?
There is also an option with a separate slot for a memory card when the tray is for SIM-In such cases, setting two communication numbers does not affect the possibility of using additional storage. Check the specification of your model on the official website or in the Settings menu. → On the phone to understand the architecture of slots.
Activation of the device and signal verification
Once the card tray is back in place, you can turn on your smartphone. Press and hold the power button until the Mi or Redmi logo appears. The boot process will take from 30 seconds to 2 minutes, while the system polls the communication module and reads the data from the card chip.
If SIM-The map is good and properly installed, and at the top of the screen (at the status bar) you'll see signal level indicators, usually vertical lines or triangles, and next to it you can see a network type designation: 4G, LTE, 5G or+. If you see a crossed-out SIM card icon or the words “No service”, then there is a problem.
When the system is first installed, it may request PIN-This is a security code that is often set to "0000" or "1234" by default, but you'd better find it on a plastic card-based card that was issued in the cabin. PUK-unlocker.
Setting up network and internet parameters
Often, once you install a card, the Internet doesn't work automatically because you don't have APN access points. Modern versions of the MIUI and HyperOS shells usually have SMS settings or download automatically. However, sometimes manual settings are required.
To check and adjust, go to the Settings menu → SIM-Select the SIM card you want (if there are two) and click on "Access Points (APN)". In the upper right corner, there may be a menu button or a reset icon. Try clicking Reset or Restore by Default so that the system prescribes the current parameters of your operator.
| Parameter | Value for adjustment | Where to find out. |
|---|---|---|
| Name (Name) | Any (e.g. Internet) | Manually crafting APN |
| Access Point (APN) | Internet (or operator-specific) | Operator's website / SMS |
| Type APN | default,supl | Automatically. |
| Protocol APN | IPv4/IPv6 | By default. |
If the automatic setting didn't work, you can find manual input data on your mobile operator's official website in the support section. Type the operator name in the search using the APN settings, and the phone often suggests you create the correct profile. After saving, remember to switch the tick to the created access point.
Diagnosis of problems: if the phone does not see the SIM
The situation when the smartphone does not respond to the installed card, is rare, but possible. First of all, check whether the gold contacts on the very same card are not contaminated. SIM-Rub them with a soft dry cloth or a slather, and make sure the card is not scratched or chipped.
If you try to remove the tray and install the card in another slot (if there are two of them), if the card is triggered in the second slot, then the problem is in the first slot or a particular communication module, and if the card is not read in any slot, it may be damaged or deactivated by the operator.
⚠️ Note: If the phone says, "Unlocking is required." SIM-"cards" and request PUK-code, don't guess it at random. Ten failed attempts to enter PUK will lead to a complete lock of the card, which can only be restored by re-issuing a new one from the operator.
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If SIM-The card is not detected in any slot after rebooting and cleaning the contacts, most likely that the chip itself is damaged card or the phone slot requires repair.
In rare cases, the problem may be software. Go to Settings → The phone. → All specs → SIM-If it says "Disable" or status is unknown, try resetting the network settings. This action will return all network settings to factory settings, but will not delete your personal files, contacts or applications.