Owning a modern smartphone from Xiaomi or Redmi implies constant access to mobile communications, but sometimes the security system can block this access by requesting a password. PIN-This is a standard data protection procedure that is activated when the phone is turned on or after restarting if the appropriate option is set in the security settings.
The situation can become critical if you forget the code or if the phone stops seeing. SIM-map MIUI In this article, we will discuss all possible lock scenarios and how to solve them. PUK-How to properly configure the access point APN for mobile internet and what to do if the device says “No network” or"SIM-map not found".
Our goal is to provide a comprehensive guide to re-enable mobile connectivity, and we will look at standard unlocking methods through the settings menu, the use of the engineering menu, and the manual configuration of network settings, and carefully follow the steps to avoid completely blocking the communication module.
Unlocking SIM-map: PIN and PUK code
The first barrier to use SIM-maps are PIN-This is a four-digit password that is often set by the carrier by default (usually 0000 or 1234), but can be changed by the user. PIN-code three times in a row, SIM-The card will be blocked and the phone will request PUK-This is a more serious security key, consisting of 8 digits, which is required to unlock a blocked PIN-chip-machine.
⚠️ Attention: Introducing incorrect PUK-10 times in a row will lead to irreversible blocking SIM-It's not going to be possible to restore it, and you're going to have to get new plastic from the carrier.
Where to find this critically important PUK-Most often it's on the plastic card you broke out of. SIM-If the card is lost, the only safe way to obtain the code is to log in to the operator's personal account via Wi-Fi or call the support service from another phone. Tele2 provide this information after confirming the identity of the number holder.
Xiaomi's smartphone code entry process standardized after three failed typing attempts PIN There will be a field on the screen for input PUK. Be very careful when typing numbers. PUK The system will ask you to come up with a new PIN-code (4-8 Only then will the communication module be unlocked and the phone will register on the network.
Setting up an APN access point for mobile internet
Often, the problem of “how to go to the SIM card” does not mean unlocking, but setting up Internet access when voice calls are working and sites are not opened. In this case, you need to check the settings of the APN (Access Point Name) access point. On Xiaomi smartphones, these settings usually come automatically via SMS from the operator, but sometimes manual adjustments are required, especially when using unlimited Internet tariffs or specific regional settings.
To enter the settings menu APN Go to the Settings path → SIM-maps and mobile networks → Choose yours. SIM-map → Access points (APN). Here you'll see a list of available profiles. If none of them are active or working, you need to create a new access point. Click "New access point" or the plus in the upper right corner of the screen.
The menu that opens has to fill in a few fields, and the most important is the Name field (anything like the Internet) and the Access Point field (APN). The Access Point is the key parameter that varies between operators. The remaining fields, such as username and password, are often left blank unless the operator has indicated otherwise. Once completed, be sure to save the profile and activate it by ticking or selecting from the list.
💡
Once you have created a new APN hotspot, be sure to restart your smartphone. Without a reboot, changes to network protocols may not take effect and the Internet will not work.
Below is a table with the current APN settings for major Russian operators that will help you set up your internet quickly:
| Operator. | Access Point (APN) | User name | Password. |
|---|---|---|---|
| MTS | internet.mts.ru | mts | mts |
| Beeline | internet.beeline.ru | beeline | beeline |
| Megaphone | internet | (empty) | (empty) |
| Tele2 | internet.tele2.ru | (empty) | (empty) |
| Yota | internet.yota | (empty) | (empty) |
Addressing the problem"SIM-map not found"
One of the most annoying problems is the message"SIM-card not found" or "Put in SIM-"card" even when the card is physically mounted in a tray, it can be caused by software failure of the shell. MIUI, Before you bring your phone to the service, you should try a number of software and simple physical methods of contact restoration.
The first thing to do is to check if you are sitting tightly. SIM-Take the tray out with a paper clip, wipe the contacts. SIM-Soft dry cloth cards (don't use alcohol or aggressive chemicals unless you're sure the card is covered) and paste back. Make sure the card cutout matches the tray shape. If that's not the problem, try software resetting network settings.
To reset network settings go to Settings → Connection and sharing → Reset Wi-Fi, mobile networks and Bluetooth. Press Reset. This operation will delete the saved Wi-Fi and Bluetooth device passwords, but return the network modules to factory settings, which often solves the problem of determining the data. SIM-map.
☑️ Diagnostics SIM-map
If the card is not detected in any phone and the contacts are clean, the chip itself may have failed. SIM-In an era of frequent smartphone swapping and nano-SIM card trimming, these are not uncommon. SIM-cards in the operator's cabin with the number.
Using an engineering menu to diagnose a network
To better diagnose SIM card and network problems, Xiaomi can use an engineering menu, a hidden interface designed for developers and testers that allows you to see the real signal level, switch network modes (LTE/3G/2G) and check the status of the radio module, which is logged in through a special code in the Phone application.
Dial the code ##4636##. If the code works, the "Verify" menu will open. Select "Phone Information." Here you will see detailed statistics: network type, signal strength in dBm, state. SIM-At the bottom of the screen there is a drop-down list "Configure preferred network type".
⚠️ Warning: Be careful in the engineering menu. Changing the settings of the radio module without understanding the process can lead to the complete disappearance of the network or the inability to make calls up to resetting settings.
Forced network switching often helps, for example, if the phone is "hanging" on 3G and does not catch 4G, or vice versa, does not see the network at all. Try selecting LTE only (4G only) or GSM only (2G only) to check if the antenna responds to commands at all. After checking, be sure to return the value to "LTE/TD-SCDMA/WCDMA/GSM" (auto).
What to do if the engineering menu code doesn’t work?
Setting up two SIM-maps and priorities
Xiaomi smartphones are famous for their support of two SIM-But if you're not setting your priorities right, you can create the illusion of a problem with access, for example, if the Internet has to work with the second SIM, and the first one is in the settings, the sites won't load.
Go to the Settings menu → SIM-maps and mobile networks. You'll see two slots here. You can customize each one separately:
- 📶 Use for calls: select a specific one SIM Or leave the question, "Always ask".
- 🌐 Use for the Internet: a critical parameter that determines which SIM will go through data traffic.
- 📩 Use it for SMS: The default is the main card, but you can change it.
There is also a “Receive Calls to Another” switch in this menu. SIM-If it is activated, the second line will not be available (or vice versa, depending on the implementation). 4G/5G This is less relevant, since they allow you to be online at the same time on both SIMs, but a voice call can still temporarily put one of them into mode. 2G/3G.
💡
The right choice SIM-Settings menu map solves 90% of missing internet problems with active balance.
Frequent errors and their elimination
Users often encounter an error called "Not logged in" or "Only emergency calls." This can mean that the phone sees the phone. SIM-The reasons for this can range from temporary problems on the operator's side to an incorrectly selected region in the settings.
Check if Flight mode is on (air mode). Sometimes the system sticks in this state. Turn on and off the air mode through the notification curtain to restart the radio module. Also make sure that your country (e.g. Russia) is selected in the Settings → Advanced Settings → Region.
If nothing helps, there may be a problem with the operating system itself. MIUI Updates often contain patches for modems that improve compatibility with the system. SIM-maps of different operators. Go to Settings → About the phone and click on the system version to check for updates.