Replacement of SIM-card Xiaomi Redmi 4: step-by-step algorithm

The process of replacing the communication element on the Xiaomi Redmi 4 smartphone may seem elementary, but the owners of this popular model often have difficulties due to the design features of the tray. Unlike modern devices that use a combined slot, it is important to correctly position the cards here so as not to damage the contacts. Any installation error can lead to the fact that the gadget will stop seeing the network or will work unstable.

In this article, we will discuss in detail the mechanics of the holder extraction, preparatory steps and software configuration after a physical replacement, you will learn how to avoid common errors and what to do if you install a new one. SIM-Your phone doesn't respond to your card. This guide will help you quickly restore communication without going to a service center.

Preparation for tray removal SIM-map

Before you start physically affecting the body of the device, you need to make sure that you are in a safe environment. It is best to do the procedure at the table in good light so that small details, such as the paper clip or the card itself, are not lost. It is also critical to turn off the device before removing the tray, although Hot-Swap technology theoretically allows you to change cards on the go, the risk of damage to the power controller is still preserved.

You will need a special metal clip that comes with a smartphone box. If the original one is lost, a regular stationery clip, straightened to the desired shape, or a special needle for the SIM will do. Do not use sharp objects like sewing needles or pins, as their diameter may be too large for the hole in the Redmi 4 case, which will lead to a stuck mechanism.

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Use only thin tools to extract the tray so as not to damage the micro-switch inside the hole.

Make sure your hands are dry and clean. Fat spots or moisture can get into the contacts of the card or inside the slot, which over time will cause oxidation and signal loss. If you change the map in the cold or in a dusty room, try to minimize the time when the insides of the phone are open to the outside environment.

Mechanics of extraction and installation of tray

Find a narrow hole on the end of the case next to a long retractable tray. In the Xiaomi Redmi 4 model, it is usually on the top edge. Carefully insert the tool perpendicular to the body and press until the characteristic click. The tray should extend a few millimeters, after which it can be removed with your fingers.

Take a close look at the extracted element. This model uses a hybrid slot, which means having two positions for Micro-SIM cards or one memory card. The positions are numbered, and it's important not to confuse them when you install them, especially if you plan to use two SIM cards at the same time. The cards should lie tight, not wobbling, but not being squeezed with force.

When you install a new card, pay attention to the location of the golden contacts -- they should look down to the motherboard, and the angle of the plastic should match the shape of the tray. Don't put too much effort. If the card doesn't come in easily, it's not installed correctly. After placing the cards, insert the tray back into the case before clicking.

⚠️ Warning: Never try to push the tray by force unless it comes in.This can break plastic guides inside the case or damage the contacts on the motherboard.

Technical characteristics and types SIM-map

Redmi 4 supports second, third and fourth generation networks, but for high-speed Internet to be fully used, the card itself must be standardized. Older Mini-SIM or Micro-SIM cards without 4G support can work unstablely or limit data transfer speeds.

The table below shows the main differences between card formats and their compatibility with this phone model, which will help you understand whether you need to contact the communication salon to replace plastic or just crop an old card (although the latter is not recommended).

It is worth noting that Xiaomi uses standard solutions for its time in this model. If your card is too old and cut out of a larger format by hand, it can get stuck in the tray, in which case it is better to order a duplicate from the operator to avoid mechanical damage to the slot.

Network settings after replacement

After switching on the phone, the system will automatically detect a new one. SIM-However, to use the mobile Internet, it often requires manual settings of access points. APN. Communications providers usually send configurations SMS, But sometimes you have to manually enter them through the settings menu.

To do this, go to the Settings. → SIM-Maps and mobile networks. Select the slot you want and find the "Access Points" item (APN)". Press the add-on button and enter the data you get from your carrier's website, usually the name of the dot and the server address.

Don't forget to check the "Use Mobile Data" switch. In the MIUI shell, traffic management is quite strict, and by default the Internet can be turned off to save battery power. Also make sure you choose the right type of network, such as LTE preferably if you are in coverage.

⚠️ Note: If you enter the settings after APN The Internet didn't work, so try to turn on flight mode for 10 seconds, and then turn it off.

Solving problems with map definition

Often, users are faced with a situation where the phone says “No”. SIM-"Calls only" or "Emergency Calls only." First, check the purity of the contacts. Wipe the golden plate of the card with a soft dry cloth or a swallow. Oxidation or fat can block signal transmission.

The second common cause is a software glitch in the communication module. Try resetting your network settings. Go to Settings → Advanced Settings → Recovery and Reset → Reset your Wi-Fi, mobile Internet and Bluetooth settings. This action will not delete your personal data, but will return your network settings to factory values.

• 📱 Check if the lock is activated. IMEI blacklist.
• 📱 Make sure the card is not blocked. PIN-cocom (entry required) PUK).
• 📱 Try inserting the card into another slot or phone to check the health of the card.

If nothing works, it may be the phone's hardware itself that causes mechanical damage to the reader's contact inside the slot, a common problem after a careless replacement, and that would require a diagnosis at a service center.

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If SIM-The card is not determined in any slot and in other phones works, a malfunction of the communication module of the smartphone itself is likely.

Use of the two SIM-mapping

Model Redmi 4 It allows you to use two SIM cards at the same time, which is very convenient for separating work and personal calls. 4G/LTE, The second will be forced into the regime. 2G/3G voice-call.

In the settings, you can choose which card will be used for mobile Internet by default, and it is also convenient to configure call scripts so that the phone asks which card to call from, or uses a specific card for specific contacts.

With active use of two cards, battery consumption can increase, as the device has to communicate with two towers at the same time. If you are in the zone of weak signal, the phone will constantly search for the network, which will quickly land the battery. In such situations, it is reasonable to turn off the second SIM card programmatically through the menu.

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