Xiaomi Redmi 4X remains a popular device due to its reliability and autonomy, but new owners often have questions when setting up equipment. One of the most common tasks is to properly install communication modules and memory cards, since the design of the tray has its own characteristics. Incorrect installation can lead to the fact that the device will no longer see the network or will not save files, so it is important to follow the sequence of actions.
Unlike many modern models, where the tray is removed on one side, this device uses a hybrid slot that requires careful handling. This is a critical step, as a hot replacement is a must-see. SIM-cards in devices with a fixed battery may cause a short circuit or software failure of the communication module.
You'll only need the original paper clip that comes with the kit, or a thin needle. Don't use thick-section paper clips or knives, as they can easily damage the latch mechanism inside the hole. Let's go through each stage of preparation and installation in detail to eliminate any risks of damage to your gadget.
Preparation of the workplace and tools
Before you start, you need to have good lighting and a clean table. Dust and small debris, when you get inside your smartphone with the tray, can oxidize contacts or disrupt the connection to the motherboard. Wipe the work area with dry cloth and prepare all the necessary components in the immediate vicinity of your hands.
Take a good look at yourself. SIM-MicroSD card and memory card: Golden contacts should be free of scratches, oxides or contamination. If you use an old SIM card that used to be on another phone, it makes sense to gently wipe the chip with a soft dry wipe. Fat spots from the fingers can cause an unstable signal.
⚠️ Warning: Never use wet wipes or alcohol to clean your contacts SIM-The fluid can leak into the slot and cause the board to corrosion.
Make sure you have a tool to remove the tray on hand.The standard metal staple from the kit has the perfect thickness for this mechanism. If it's lost, choose a pin or needle, but act extremely carefully so as not to bend the mechanism inside the hole. The pressure should be strictly perpendicular to the body.
Tray design and card types
The tray in Redmi 4X is hybrid, which means that you can install two Nano-SIM SIM cards or one SIM card and one microSD memory card. It is important to understand that you will not be able to use two SIM cards and a flash drive at the same time - you will have to choose one of the configuration options.
Nano-SIM is the smallest standard in existence, and if your card is larger (Micro or Mini), you need to cut it out or order a new one from the operator, and using homemade adapters or artisanal cut cards with geometry infringing can lead to a tray getting stuck.
What to do if the SIM card is not suitable in size?
The memory card must meet the specification of MicroSDHC or MicroSDXC. The device supports cards up to 128 GB, although many users successfully use 256 GB. Write speed is better to choose the UHS-I class (Class 10) to avoid delays when saving photos and videos.
Step-by-step instructions for removing the tray
Find a small circular hole on the bottom of your smartphone, next to the charging socket and microphone, and look carefully at the frame: the hole is on the moving tray, not on the stationary part of the case.
Insert the tip of the paper clip into the hole strictly perpendicular. You don't need to enter the tool deeply, just feel the light support of the mechanism. Press with moderate effort until the characteristic click and easily extend the tray outwards.
- 📱 Make sure that the smartphone lies on a soft surface with the screen down, so that when the tray jumps out sharply, it does not fall on the hard floor.
- 🔍 Consider the extracted tray: one side has a notch under Nano-SIM, the other - under MicroSD or a second SIM card.
- 🔧 If the tray is not removed, do not pick the hole wider - it is better to slightly change the angle of the needle, finding the right stop in the latch.
Once removed, place the tray on a flat surface with the contacts upwards. Notice the bevelled angle on the tray, which corresponds to the same notch on the map. This geometrical match does not allow you to set the map incorrectly if you act without excessive force.
Installation of SIM-card and memory card
The installation process requires care, because the contacts must fit tightly into the site. Take a Nano-SIM card and place it above the appropriate place on the tray. The bevelled angle must match the marking on the metal.
☑️ Pre-installing check
Place the card in a notch. It should lie flat, not protruding beyond the edges of the metal frame. If the card is raised or dangling, it means that it is installed incorrectly or has a defect. In some cases, easy finger pressing before clicking helps, but most often the card just falls within its boundaries.
If you're using a memory card, insert it into the second compartment of the tray, and it's also important to keep track of the contacts' orientation -- they have to look down to the inside of the tray -- the memory card is usually tighter and may require a little pressure to enter the slots.
⚠️ Warning: Do not insert cards into the tray while it is inside the phone.This can cause the mechanism to break or damage the contacts on the edge of the hole.
Once you've placed all the modules, check their position again, the cards should not overlap or project beyond the metal edge, the tray should look smooth, without distortion.
Inserting the tray back into the smartphone
Take the tray with two fingers, try not to touch the golden contacts. Hold it to the hole in the case. It is important to observe the correct orientation: the bevelled corner of the tray should look in the same direction as the sample extracted.
Put the tray in the guides to the point. You don't have to use force -- if the tray is tight, it's skewed. You have to feel the soft stroke of the mechanism. The end point is when the outer edge of the tray equals the frame of the body.
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If the tray doesn't come in, don't push harder. Take it out and check if the corner of the map is wrapped or if the dust is in the guides.
Once installed successfully, you can turn on the device. Press and hold the power button until the Mi logo appears. The system will start loading, and network indicators should appear on the screen during the initialization of communication modules.
Network setup and operation check
When you turn on your smartphone, go to the settings. Usually, the system automatically detects a new SIM card and requests it. PIN-Enter the code provided by the operator to unlock access to the network.
To check the memory card, open the Explorer or Files app. The storage list should show the internal drive and the external SD card. If the card is not visible, try restarting the device again.
In settings Two. SIM-You can assign roles to each card, and you can choose which SIM to use for default calls and which to use for mobile Internet, and this is especially useful when using tariffs from different operators.
| Parameter | Slot 1 | Slot 2 (Hybrid) |
|---|---|---|
| Type of card | Nano-SIM | Nano-SIM or MicroSD |
| 4G support | Yes. | Yes (with one active SIM) |
| Max. SD volume | - | up to 128GB (officially) |
| Hot replacement. | No. | No. |
Check the signal level. If it's weak, make sure the map is tightly set. Sometimes it's enough to remove and insert the tray again to restore contact. Make sure the settings don't turn on flight mode.
Possible problems and solutions
One of the common problems is the message «SIM-This may indicate contact contamination or software failure, try erasing contacts with an eraser (neatly, only the card metal) and blowing the slot in the phone with compressed air.
If the phone doesn't see the memory card, check its formatting. Android works best with the FAT32 or exFAT file system. If the card has previously been used on a device of another system (such as Linux or macOS), it may need to be formatted via the smartphone menu.
⚠️ Note: Formatting a memory card will remove all data from it. Be sure to back up your files on your computer before this procedure.
In rare cases, the problem lies in the tray itself, the methyl contacts on it can oxidize or deform, visual examination will help identify black spots or dents, in which case you may need to replace the tray in the service center.
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Most card definition problems are solved by clean installation, rebooting the device, or properly formatting the drive.
If nothing works, try checking the SIM card on another phone to prevent card malfunction or carrier-side problems, sometimes locking old SIM cards with prolonged inactivity.