When your Xiaomi stops seeing the SIM card, it always takes you by surprise, especially if you're waiting for an important call or working remotely. The screen can show a crossed-out SIM, an icon "No network" or endlessly search for carriers. This does not always mean a phone breakage, often the problem lies in a software failure or banal contamination of contacts.
Before you carry the device to the service center, it is worth conducting a thorough diagnosis yourself. The hardware of the smartphone can be healthy, and the failure is corrected by a simple reboot or the correct installation of the tray. In this article, we will analyze all possible causes, from the simplest to the most complex, and offer a step-by-step plan of action.
The problem cannot be ignored, as the lack of communication blocks access to mobile Internet and calls, and we will look at methods that will help restore the functionality of the communication module in the home without the use of complex equipment.
Primary diagnostics and visual examination
The first step is always to look carefully, take out the SIM card tray and see if it's inserted correctly, the bevelled corner should match the tray shape, and the map should lie flat, without protruding beyond the edges, and if the tray is skewed, the contacts may simply not reach the pad inside the phone.
Notice the state of the SIM card itself, if it's very old, hand-carved from a large card, or scratches on golden contacts, it could be causing a failure, and in such cases, the GSM module cannot read the subscriber's identification code.
⚠️ Warning: Never use alcohol or aggressive chemistry to clean the SIM card contacts. use only dry lilaless cloth or eraser to gently polish the chip.
Also check the tray for mechanical damage. If it is deformed or oxidized, the contact may be broken. Try inserting the SIM card into another slot if your smartphone supports Dual SIM. This will help you understand whether the problem is in a particular card or in the slot of the device.
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Try installing your SIM card on another phone, and if it works there, it's your Xiaomi, not your carrier, that's the problem.
Software reset and reboot of the device
Often the reason Xiaomi doesn't see the SIM is a temporary malfunction in the MIUI or HyperOS operating system. The communication module could "hang" and stopped polling the slot. The simplest solution is a complete reboot of the device.
Don't limit yourself to a normal shutdown. Press the power button and select "Reset." If the screen doesn't respond, try a forced reset by holding the power button near the power button. 10-15 It's just seconds before the logo comes in, and it'll help you reset the cache of the system processes.
If a simple reboot didn’t work, try a more radical method: resetting your network settings, which will bring your Wi-Fi, Bluetooth, and mobile network settings back to factory values, but won’t delete your personal files or contacts.
☑️ Algorithm of resetting network settings
Once you do this, the phone will start registering again on the operator's network, which can take anywhere from one to five minutes, and if the network status has not changed, move on to a deeper analysis of the settings.
Network settings and operator selection
There are options in the smartphone settings that can block the SIM card. Go to the Settings menu → SIM-Maps and mobile networks. Make sure the slot is activated. Sometimes, after the system update, the settings may get lost and the slot is turned off software.
An important parameter is "Network type of preference." If you have an old tariff or are in a low coverage area, the automatic choice may not work correctly. Try switching from 5G/4G to 3G or 2G to check. If the network appears, then there is a problem with coverage or frequency compatibility.
| Parameter | Recommended value | When to change |
|---|---|---|
| Type of network | LTE is preferred | Always for maximum speed. |
| Data roaming | Off. | If you're not abroad |
| Choice of network | Automatically. | In most cases, |
| Access Points (APN) | If the internet doesn't work |
You should also check the manual operator selection. Turn off automatic search and try to find available networks manually. If your operator appears on the list, select it. If the list is empty or the selection fails, the problem may be deeper.
IMEI and radio status check
One of the most critical diagnoses is the absence of an IMEI. Type *#06# into the dialer. If the number does not appear on the screen or the number is "Null" / "Unknown" instead, this means that the system does not see the radio module.
IMEI is your device's unique identifier, and without it, your phone can't log in, and the absence of that number often indicates a software firmware failure or, in the worst case, a motherboard failure.
If the IMEI is displayed but the network is not catching, check the SIM status in the settings menu. It should say "On the network" or the operator's name. If it says "Unknown" or "Disabled", try to extract and paste the card again when the phone is turned on (although officially this is not recommended, sometimes this helps the system to re-snatch the device).
⚠️ Attention: If IMEI lost after updating the system or unsuccessful flashing, independent actions can lead to a complete locking of the device.
Physical damage and contact cleaning
Over time, the contacts in the tray can become oxidized or infused. Take a bright lamp and flashlight to look inside the slot. You should see the spring-loaded contacts (pins). If one of them is bent or missing, contact with the SIM card is impossible.
You can use a soft bristling toothbrush or compressed air to clean the slot, gently walk through the insides of the slot, removing dust and pile. Sometimes the problem is solved by adding a micro-pad (a piece of paper) to the back of the SIM card to fit tighter to the contacts, but this is a temporary solution.
Check the integrity of the SIM card itself, if the chip is damaged, it cannot be repaired, in which case you need to contact your carrier's salon to replace the SIM card with a saving number, usually free or inexpensive procedure.
Can I restore the SIM card on my own?
Resetting to factory settings as an extreme measure
If the software methods don't work, there's a complete reset.This will delete all the data from the phone, so be sure to back up.Reset eliminates the impact of third-party applications and deep system configuration errors.
Go to Settings → About Phone → Settings Reset → Erase all data. Once rebooted, the phone will look like new. Insert the SIM card at the initial setup stage. If Xiaomi doesn’t see the SIM after that, the probability of hardware failure is 99%.
Sometimes the problem is with a particular firmware version, and if you're using a custom build or a global version on a Chinese machine, there may be frequency conflicts, and then flashing to a stable version for your region through a computer will help.
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If after a complete reset and check the SIM card in another phone network did not appear – the problem lies in the antenna module or the plume of the smartphone itself.