Smartphones from Xiaomi have long established themselves as affordable and functional devices, and the Redmi 4 model was no exception. SIM-It allows users to manage communication costs flexibly or separate work and personal contacts, but despite the simplicity of the design, the process of installing or replacing cards can raise questions for those who are first encountering a similar tray form factor.
In this article, we will discuss in detail how to properly prepare the device, what tools you will need and how to avoid common errors that can damage contacts or the case. Proper installation of a nano-SIM card guarantees a stable signal and a long slot life. Ignoring simple safety rules can lead to malfunctioning of the communication module, so carefully follow each step of the instructions.
Before you start physically removing the tray, you need to make sure that the device is turned off. Although modern smartphones often support hot replacement, the MIUI software installed on Redmi 4 better recognizes new cards after restarting the system. This will also eliminate the risk of short circuit in the power supply of the communication module if the contacts of the card or tray accidentally closes when the electric current is active.
⚠️ Note: Before any manipulation of the tray for SIM-Be sure to turn off your smartphone to prevent damage to the motherboard’s electrical contacts.
Tools and workplace preparation
You don't need complex hardware to successfully install a second SIM card, and the whole process takes no more than two minutes if you're prepared in advance, and the main tool is a paper clip that comes with your smartphone, or an analogue that you can find in any office drawer.
Make sure your hands are dry and clean. Fat marks or dust can get inside the slot and worsen contact between the gold patches of the card and the phone's reader. If you have soft lilaless cloth on hand, wipe the tray before installing the card.
☑️ Pre-installing check
It is important to check the size of your SIM-Xiaomi Redmi 4 model works exclusively with Nano-SIM format, which is the smallest of the existing standards. If your cards are larger, they need to be gently cut along the contour or replaced by a carrier, as inserting a larger card can physically damage the tray mechanism.
Tray Anatomy and Slot Search
Tray for SIM-The maps in Redmi 4 are located on the top end of the device's body. This is standard for many Xiaomi smartphones from that period. To find a hole to extract, carefully examine the top edge: you will see a small circular hole next to an oblong plastic tray.
The tray design in this model has its own features: it supports either two Nano-SIM cards, one Nano-SIM and one microSD memory card. It is important to understand that the second slot is a combined slot, meaning you can not use two SIM cards and a memory card at the same time, unless you use special adapters that are not recommended for use due to the risk of getting stuck.
What to do if the tray is not removed?
Notice the shape of the card cutout, and the tray has a dotted line or map silhouette that shows the correct position of the chip, and the card contacts should look down to the motherboard, and the bevelled corner of the card should match the shape of the cutout.
Removal and installation process SIM-map
Take a paper clip and insert its sharp end into a round hole on the end of the smartphone. The movement should be confident and perpendicular to the body. You will feel a slight click and spring resistance - this is a signal that the mechanism is unlocked. The tray will slightly extend outwards, after which it can be pulled out completely with your fingers.
Put the extracted tray on a flat surface. Make sure you don't confuse the orientation of the tray. In the Redmi 4, the slots are numbered. Usually, the SIM 1 is for the main card and the SIM 2 is for the extra card. Place the first card in the appropriate recess, making sure it's tight and not wobbling.
Then set up the second one. SIM-You can move the card to the second slot, and you can move the first card carefully, and if you're using the memory card instead of the second SIM, you can place the microSD in the remaining place, and you can also keep the contacts in the downward orientation.
- 📱 Put the paperclip in the hole until you feel the click of the spring.
- 🔻 Make sure that the golden contacts are SIM-The cards are directed downwards to the table surface (or upwards, if you look at the tray from above, but with a chip to the phone contacts).
- 📐 Check that the beveled corner of the card matches perfectly with the shape of the cutout in the tray.
- 🔒 Make sure the card does not protrude above the edges of the tray, otherwise it may get stuck when inserted.
Once you've installed the cards, gently insert the tray back into the smartphone body, so it's important not to confuse the sides: the tray only enters one side. If you feel resistance, don't push, turn the tray 180 degrees. A properly installed tray enters smoothly and to the end, leveling with the frame of the case.
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To make the tray enter easier, you can slightly wipe its end part with a dry soft cloth, removing possible dust or oxides.
Network settings after installation
Once the tray is installed, turn on your smartphone. Android system with a shell MIUI automatically detect new SIM-You may see a request for input on the screen. PIN-If you have the code on the cards, enter the code provided by the operator.
Next, check your network settings. Go to the Settings menu, then select Two. SIM-maps and mobile networks (or SIM-In this section, you'll see both cards installed, and you can assign which cards will be used for mobile Internet and which for default voice calls.
| Parameter | Description | Recommendation |
|---|---|---|
| SIM 1 | The main slot | Use for a card with better coverage or basic fare |
| SIM 2 | Additional slot | Best for rates with cheap minutes or internet |
| Mobile Internet | Choosing an active card | Choose a card with unlimited traffic or a large package of GB |
| Voice calls | Default choice | You can choose each time or assign a primary |
In the same menu, you can configure switching between networks. 2G, 3G and 4G. For Redmi 4, it is recommended to set the network type. 4G, to ensure maximum data transfer speed if your SIM-The cards support this standard.
Addressing common problems
Sometimes, after you put in a second SIM card, it may not be determined by the system. First of all, check if it's inserted correctly. SIM-cards with a soft swallow or alcohol napkin, then install again.
If the phone says "No network" or "Emergency calls only", check the access point settings (APN). Often, for mobile Internet to work, you need to manually prescribe the operator's parameters, this data can be found on the official website of your provider or obtained automatically via SMS.
⚠️ Warning: If the smartphone can’t see SIM-card after several attempts to reboot and clean contacts, possibly damaged the tray itself or the reader module on the board.
Another cause of problems may be frequency incompatibility. Xiaomi Redmi 4 has a global version and version for the Chinese market. Make sure your phone supports the LTE Band 3, 7, 20 frequencies used by operators in your region. You can check the supported frequencies on the engineering menu or on the manufacturer's website.
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Most problems with the definition of the second SIM-cards are solved by simply restarting the device or re-installing the card with the contacts cleared.
Features of working in the mode of two cards
Using two active SIM cards in Redmi 4 has its own power consumption nuances: When both cards are running in standby and network search, battery consumption increases. If you are in an area of uncertain reception, the phone will waste even more energy to maintain the signal.
Keep in mind that when you are actively talking on one card, the second card may temporarily go into 2G mode or become unavailable, depending on the network settings and VoLTE technology. If it is critical for you to be in touch with both numbers at the same time, activate the “Redirect” function for the second card in case it is busy or unavailable.
- 🔋 Two active SIM-The card increases the battery consumption to 15-20% day-to-day.
- 📶 With a weak signal of one of the cards, the phone can more often switch between towers, which warms the processor.
- 📞 Make sure that roaming is disabled on both cards if you do not plan to travel abroad.
To optimize the work, you can set up profiles, for example, at night, a second SIM card can be temporarily disabled through the settings menu to give the phone a rest and save charge if calls to this number are not expected.
Can I use a memory card and two SIM cards at the same time?
What to do if SIM-Old format map (Mini or Micro)?
Why is the second SIM card not catching 4G?
Following these guidelines, you can easily configure the two numbers on your Xiaomi Redmi 4. Proper installation and configuration will ensure stable communication and comfortable use of all the functions of the smartphone. Remember that accuracy when working with small parts is the key to the durability of your device.
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Redmi 4 hybrid slot allows you to choose between a second SIM card and a memory extension, but does not support their simultaneous operation without special (and risky) adapters.