Modern Xiaomi smartphones, particularly the legendary Redmi 4 series, often require the user to intervene in the design of the case to replace the drive or SIM card. Unlike flagships with a sealed body, it often provides a removable battery, which gives the owner more freedom.
In this guide, we will discuss in detail how to insert a SIM card in Xiaomi Redmi 4, and also consider the nuances of working with a slot for microSD memory cards. We will pay special attention to the correct orientation of contacts, since positioning errors cause 90% of network definition problems.
Before you start physically affecting the device, we strongly advise you to turn it off. Although modern power controllers have protection against static electricity, you should not risk the integrity of the motherboard. Preparing the workplace is the first step to successfully install any modules.
⚠️ Attention: If you feel resistance to inserting a card, do not use force. You've probably broken the angle of inclination or confused the sides of contact. Forced pressure can break the contact pins inside the slot.
Preparation of the workplace and tools
To work comfortably, you'll need a clean, well-lit surface: fine parts like a SIM card tray easily lost or falling into hard-to-reach places. Make sure there are no water sources or static electricity nearby that can damage electronics.
The main tool will be a special paper clip, which comes in the kit, or its analogue. It is important that the tool is not more than 1 mm thick, so as not to damage the extraction mechanism. If there is no paper clip, you can use a thin needle, but act extremely carefully.
It is also recommended to have a soft fabric or microfiber on hand, which is useful for wiping the contacts of the memory card or SIM card before installation, fatty fingerprints from the fingers can degrade the quality of the connection and cause periodic communication breaks.
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Use an antistatic bracelet or simply touch a grounded metal object before starting work to remove static charge from the body.
Anatomy of slots in the line of Redmi 4
The Redmi 4 series is heterogeneous and divided into models with removable and non-removable battery. This depends on the algorithm of your actions. The Redmi 4A and Redmi 4X models have a classic design with an opening rear cover, while the base Redmi 4 (Prime) has an all-metal body.
In removable battery devices, SIM card slots are often placed under the battery, requiring the complete removal of the back panel, using a retractable tray on the end of the device, and understanding the design of your gadget is key to success.
Note the marking next to the slots. Usually the manufacturer specifies SIM 1, SIM 2 and SD. In combined slots (hybrid) installation of two SIM cards blocks the ability to use the memory card, so the choice of configuration depends on your priorities.
| Model of the device | Type of body | SIM location | 4G support |
|---|---|---|---|
| Redmi 4A | Plastic, removable battery | Under the battery. | Yes (LTE) |
| Redmi 4X | Metal, non-removable battery | End tray. | Yes (LTE) |
| Redmi 4 (Prime) | Metal, non-removable battery | End tray. | Yes (LTE) |
| Redmi 4 Pro | Metal, non-removable battery | End tray. | Yes (LTE) |
Instructions: How to insert SIM into Redmi 4A (removable battery)
The process of installing a Redmi 4A SIM card starts with turning off your smartphone. Find a small slot on the bottom end, put a nail or a plastic blade on the back cover and carefully remove it, and you will have access to the battery.
If the battery is installed, it needs to be removed. Carefully pull the special ledge at the bottom of the compartment to lift the battery, and disconnect it. Under the battery, at the top of the compartment, you'll see two SIM card slots and one for the memory card.
Take a Nano-SIM SIM card (small). Notice the cut angle -- it should match the pattern next to the slot. Plug the card into the SIM 1 slot before the click, then do the same with the second card in the SIM 2 slot. Once installed, put the battery back in place, pressing its contacts tightly against the phone terminals, and close the lid.
☑️ Installation SIM redmi 4A
Install SIM card and SD in Redmi 4X and Prime (whole case)
Non-removable battery models like the Redmi 4X use a retractable tray. Find a round hole on the bottom or top of the device next to the elongated tray. Insert the paper clip into the hole perpendicular to the body and press slightly before the mechanism clicks.
The tray will extend a few millimeters, and then you can pull it out with your fingers. Notice the shape of the cells: one is for Nano-SIM, the other can be for either a second SIM card or a MicroSD card, depending on the firmware version and region.
Put the SIM card in the appropriate cell, making sure that the golden contacts look down (or up, according to the scheme on the tray). The card should lie flat, not protruding beyond the edges of the frame. Carefully insert the tray back into the phone to the end. Don't skew it so as not to break the internal guides.
⚠️ Note: In hybrid slots, you can not use two SIM cards and a memory card at the same time. You will have to choose between two SIMs, or one SIM and a flash drive.
What to do if the tray is not moved?
Working with a MicroSD memory card
Expansion of memory is a common reason to turn to a card slot. Xiaomi Redmi 4 supports cards up to 128 GB (officially) and often more in practice. The card file system must be FAT32 or exFAT for proper operation.
When installed in a separate slot (if any), simply insert the card before the characteristic click. If the slot is combined, make sure you use the correct adapter or the card of the right size. Once the phone is turned on, the system must automatically recognize the new media.
If the card is not identified, try to clean the contacts with soft dry cloth. Sometimes oxidation of the contacts leads to loss of connection. Also check the card on another device to rule out physical malfunction.
- 📱 Make sure the card is inserted before clicking and lies flat.
- 💾 Format the card only through the phone menu for maximum compatibility.
- 🔒 Lock slider on the adapter SD should be in the unlocking position.
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A properly installed memory card should not protrude outside the housing or stagger in the slot. Any shift leads to data loss.
Diagnostics of map definition problems
There are times when, after you install a SIM card, your phone says, "No SIM card" or "Emergency calls only." First, check if the slot is activated in the settings. Go to Settings. → SIM-maps and mobile networks and make sure the switch opposite the desired slot is on.
If the problem persists, the contacts may have become contaminated or oxidized. Rub the SIM chip with a stripe or an alcohol wipe. It's also worth checking if the card itself is deformed - sometimes when you cut out from Mini or Micro format, the geometry of the chip is broken.
In rare cases, you need to reset your network settings, which won't delete your personal data, but will return the connection settings to factory values, and after the reboot, the phone will try to re-register with the operator's network.