How to change the SIM on Xiaomi Redmi 9: the complete guide

Changing a carrier or switching to a tariff with a large amount of Internet traffic often requires a physical replacement. SIM-Owners of the popular budget smartphone Xiaomi Redmi 9 may face the question of how to correctly and safely perform this procedure, so as not to damage the device.

The process of replacing a card does not require special technical skills, but requires accuracy and understanding which slot to install. Modern Xiaomi smartphones often use combined trays, where space for a second SIM card can be occupied by a microSD memory card. It is important to determine in advance what format you need: a dual SIM card or one SIM card plus memory expansion.

In this article, we will take a look at all the steps of replacement, from finding a paper clip to checking the network signal after turning on. You will learn about the nuances of nano-sims, the features of the Redmi 9 tray and how to solve typical network definition problems.

Preparation of the workplace and necessary tools

Before you start manipulating the case of a smartphone, you need to ensure comfortable working conditions. It is best to replace the SIM card at a table with good lighting, so that the small details are clearly visible. A lost tray or a fallen SIM card can be a serious problem if you fall into a difficult place.

The main tool to remove the tray is a special metal clip that comes with the device. If the original paper clip is lost, you can use a regular stationery clip by straightening one of its ends, or a thin needle. Importantly, do not use knives, pins or other sharp objects that can slip and damage your finger or smartphone screen.

⚠️ Warning: Before removing the tray, it is strongly recommended to turn off the smartphone. Although modern phones support hot replacement, software failures when reading a new card are possible, and the device turned off guarantees the safety of contacts.

Prepare a new one, too. SIM-Nano-SIM card. This is the size used in Redmi 9. If your card is larger, use an adapter or ask the carrier to replace the card with a nano format. Don't try to cut the old SIM yourself with scissors, as you can damage the chip or disrupt the geometry of the board.

Features of the design of the Redmi 9 tray

The sim card tray in Xiaomi Redmi 9 is located on the bottom end of the device, next to the USB Type-C charging connector. This is the standard location for most modern smartphones, but the design of the tray itself has important differences from previous models.

Hybrid means that the user has the choice of using two SIM cards at the same time or one SIM card and a MicroSD memory card. It is impossible to occupy all three slots (two SIMs + memory) at the same time. There is usually a schematic image on the inside of the tray that tells you how to stow the cards correctly.

The second slot often has a spring mechanism or a special notch to fix the memory card. When you install the second SIM card in this slot, it should lie tight and not stagger. If you plan to use the memory card, make sure that the contacts on the tray correspond to the type of card you install.

Step-by-step process of tray extraction

Find a small circular hole on the bottom of your smartphone next to the rectangular frame of the tray. Take a prepared paper clip or needle and insert it perpendicularly into the hole. The movement should be confident, but without undue effort, so as not to damage the ejection mechanism.

Press until you click and you extend the tray lightly. Then you gently pull the tray over the protruding edge. Don't pull sharply so you don't bend the metal contacts inside the smartphone. The tray should come out smoothly.

If the tray is not being removed, check if you hold the tool correctly. It must come in vertically, sometimes the factory lubrication or dust can make it difficult to move, in which case you can slightly sway the paperclip from side to side, increasing the pressure.

⚠️ Warning: Never insert a paper clip into a microphone next to the tray opening, which can cause permanent damage to the microphone and problems with sound when talking.

Once you've extracted it, you'll see two card areas, one for the main SIM card, one for either the second SIM card or the memory card, and you'll notice the bevelled corner of the cards that helps you navigate them properly when you install them.

Proper installation of new SIM-map

Take a new Nano-SIM card. Make sure the golden contacts are down to the tray contacts. The bevelled corner of the card should match the bevelled corner of the tray. In Redmi 9, the cards are usually set down by the contacts.

Carefully place the card in the appropriate slot. It should lie in the notch perfectly smoothly, without gaps and protruding beyond the edges of the tray. If the card is not tight or its edges are raised, you may have confused the side or format of the card.

If you use a second microSD card slot, the procedure is similar. Memory card contacts also head down. After you install both cards (or one card and one SIM), check their position again before inserting the tray back into your phone.

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Use tweezers with plastic tips for installation SIM-If your fingers are too large to handle the nano-sim, this will reduce the risk of card bias when you insert the tray.

Put the tray back in your smartphone. Notice the shape of the tray -- it has only one correct orientation. Don't force it. If the tray doesn't come in easily, take it out, flip it 180 degrees and try again. Bring the tray to the end so it matches the body.

Initial network setup and activation

After you physically install the card, turn on your smartphone. MIUI It will automatically detect a new SIM card, and it may be asked to enter on the screen. PIN-If you have previously installed the code, enter the code provided by the operator.

Go to the settings by going to the Settings menu → SIM-You'll see a list of cards installed here, make sure the switch in front of the new card is activated, and if there are two cards, the system will suggest setting preferences for calls and the Internet.

To access the mobile Internet, you need to check the APN settings (access points). These are usually downloaded automatically when you first connect to the operator's network. If the Internet is not working, go to the access point settings and select your operator's profile from the list or create a new one manually using data from the operator's website.

Check the signal level in the top right corner of the screen, and if you see a 4G or LTE icon and a signal scale, it's a success, try to make a test call or open a web page to check the connection.

Possible problems and ways to solve them

Sometimes, after you replace your SIM card, your smartphone may not see the network, so you can try to reboot your device, so you can re-interview the communication module and register with the operator's network, and often it solves 90 percent of the card problem.

If the reboot didn't work, remove the tray and wipe the SIM card contacts with a soft dry cloth that could have left fat or dust that disrupts the connection, and check if the contacts on the smartphone tray itself have oxidized.

In rare cases, the problem may be frequency incompatibility or locking your phone over IMEI. Make sure your Redmi 9 is not a carrier-specific device (relevant for devices purchased abroad).

⚠️ Note: If the phone is writing "SIM-The card is not installed" or "No network" all the time, try inserting this SIM card into another phone. If it doesn't work there, the problem is the card itself, and it needs to be changed in the operator's cabin.

In the event of software failures, network resets can help. Go to Settings → Connection and Sharing → Reset Wi-Fi, mobile networks and Bluetooth. This action will return network settings to factory values, but will not delete your personal data.

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If it's new SIM-The card is not detected in any device, most likely it is defective or not activated.

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Regular cleaning of contacts SIM-Cards and trays help to avoid problems with unstable signal and sudden loss of the network.