Installing a carrier card is the first step to take after unpacking a new smartphone. Xiaomi, Redmi and Poco brand devices have a unified tray design, but users often have questions about the compatibility of sizes and contacts. Incorrect installation can lead to the network not appearing, or, in the worst case, to mechanical damage to the slot.
In this article, we will discuss in detail the process of installing a SIM card, starting with finding a special tool and ending with checking the signal. We will look at the nuances of working with hybrid trays, where in addition to two sims, a memory card can be placed, and also discuss the features of modern models without a standard 3.5 mm connector.
The correct orientation of the chip relative to the reader's contacts is critical. The Nano-Sim card has a bevelled angle that serves as the only true reference point for installation, and ignoring this rule or trying to force the card into the wrong position is unacceptable.
Preparation for installation and search for tray
Before starting the procedure, make sure the device is turned off. Although most modern smartphones support hot SIM card replacement, it is often recommended that the manufacturer install the device when the power is turned off for initial setup and recognition of the network, which ensures that the communication module is properly initialized by the MIUI or HyperOS system on the first start.
Find a narrow oval-shaped hole on the body of your smartphone. Depending on the Xiaomi model, it can be located on the bottom end (near the USB Type-C charging port) or on the side edge. In budget and medium-sized models, the tray is often combined with a headphone jack, which requires special care when extracting.
To remove the tray, use a special metal key (clip) that comes with the kit. If the original tool is lost, a regular straight-line stationery clip or a thin needle will do. It is strongly recommended not to use eye-stitched sewing needles or thick pins, as their diameter may exceed the permissible one, which will lead to jamming of the mechanism or damage to internal sensors.
⚠️ Warning: When removing the tray, hold the smartphone firmly.A sharp spew of the tray under the action of a spring can cause it to fall and lose, especially if you are outside or over a hard surface.
Insert the tool point into the hole perpendicular to the body and press with moderate force until clicked. The tray should extend a few millimeters, after which it can be removed with your fingers.
Definition of tray type and SIM format
The retrieved design element can be of different configurations: modern flagship and mid-budget models use a triple tray, allowing you to install two SIM cards and a microSD memory card at the same time. In older or specific versions, the memory slot may be missing or combined with a second SIM card.
The de facto standard for all current smartphones is the Nano-SIM format, the smallest size of a SIM card, almost the size of a chip. If you have a larger card (Micro or Mini), it must be replaced in the cabin of the operator or carefully trimmed in a special form, although the latter method carries the risk of damaging the contacts.
Look carefully at the tray. It usually has a schematic image showing how the card should lie. Often one side of the tray is for the first SIM, and the other for the second or memory card. It is difficult to confuse the sides because of the different shapes of the cutouts, but you don't need to apply force.
Step-by-step installation instructions
The installation process requires attention and good lighting, so you can put the tray on a flat surface or hold it on a weight with the contacts clearly visible, and the main task is to match the bevelled corner of the map with the corresponding ledge in the tray's lobe.
☑️ Algorithm of SIM card installation
Place the SIM card so that the golden contacts are pointed up (if the tray is lying cutouts to you) or down (if you insert the tray into the phone,_contacts_ In most cases, Xiaomi uses a scheme where the contacts of the map are pointing down to the contacts of the phone when the tray is inserted.
Once the card has been laid in the cutout perfectly smoothly, without gaps or edges, you can insert the structure back into the case. Push the tray with your finger until you click it right. It should match the phone case.
If the tray doesn't enter the end or there's a lot of resistance, immediately stop the pressure. Remove it and check the orientation of the map again. Forced indentation can break the plastic guides inside the case.
Features of hybrid slots
Many users face confusion when using hybrid slots, a mechanism where the second place either accepts the second SIM card or the microSD card, but not at the same time.
If you want to use two SIM cards, the memory card is not installed in the slot, but if you are critically important external memory, you will have to abandon the second physical SIM card in favor of one communication module and SD card.
Can I use two SIMs and a memory card at the same time?
There are models with a separate, third memory card slot that doesn’t conflict with SIM cards. To find out the type of your device, consult the specification on the box or official website. Usually, the presence of a separate slot is referred to as a “Triple Slot”.
Compatibility table and formats
For a better understanding of the differences between formats and tray types, use the table below to help you quickly navigate your device’s specifications.
| Type of device | SIM format | Support for SD | Location of the tray |
|---|---|---|---|
| Xiaomi Redmi Note (new) | Nano-SIM | Separate slot | Lower end |
| Xiaomi Mi Series | Nano-SIM | No (memory only) | Lower end |
| Poco X / M Series | Nano-SIM | Hybrid slot | Lower end |
| Older models (up to 2016) | Micro-SIM | Under the battery. | Back (removable cover) |
Note that in models without a removable battery, the slot is always on the end. In very old models with a removable lid, the tray could be located under the battery, but such devices are rare today.
Primary setting and activation
Once you physically install the card, turn on your smartphone. The system automatically detects a new module. A PIN request may appear on the screen. This is the SIM card protection code (usually 0000 or 1234 if you haven't changed it) that is different from the screen unlock password.
If the SIM card is undecided, go to the settings menu. The path usually looks like this: Settings → SIM-You can see the status of each card here, and if it shows "No card," try to wipe the SIM contacts with a soft dry cloth and re-installe them.
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Use a soft bristling toothbrush to clean the SIM card contacts carefully if they are oxidized or contaminated.
In the same menu, you can configure a priority SIM card for calls and mobile Internet. For stable 4G/5G, make sure that the "Network Type" value is selected Preferably LTE.
Frequent problems and their solution
One of the common problems is saying, "No network," or constantly searching for the network, and it can be not only because of a wrong installation, but also because of a software failure. Try resetting the network settings.
⚠️ Note: Resetting network settings will remove stored Wi-Fi passwords and paired Bluetooth devices. Make sure you remember passwords from important networks before performing this operation.
To reset, go to Settings → Connection & Sharing → Reset Wi-Fi, mobile networks and Bluetooth. Once rebooted, the phone will re-register on the carrier’s network.
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If the phone doesn’t see the SIM card after three attempts to reinstall and reset the settings, the problem may be physical damage to the card itself or the reader slot.
It's also worth checking if the SIM card is locked by the operator, call support or paste the card into another phone to check, and if the other device is working, you may need to change the tray at the service center.