When Xiaomi’s flagship smartphone suddenly loses its network in its usual place, it can take anyone by surprise. Often the problem lies not in the hardware breakdown of the antenna, but in software failures or incorrect settings of the MIUI radio module. You can restore stable signal reception yourself without contacting the service center.
In this article, we will discuss effective methods that will help Xiaomi Redmi, Poco or Black Shark catch the network confidently again. You will learn about the hidden functions of the engineering menu, the right choice of LTE frequencies and optimization of system parameters for specific regions.
Before we get to the complex manipulations, we should rule out the trivial causes of communication deterioration. Sometimes a simple reboot or change is enough. SIM-The signal level is returned to the maximum values.
Basic Diagnostics and Physical Factors
The first step should always be to check the physical condition. SIM-Microscopic oxides on the contacts can create resistance that critically reduces the quality of the connection to the base station. Carefully remove the tray, wipe the contacts of the card with soft cloth and set it back until the characteristic click.
It is important to consider the impact of security accessories on the operation of antennas. Metal bumpers or cases with magnetic holders can shield the signal, especially in areas of uncertain reception. If you use Xiaomi in a metal case, try to remove the case and check whether the number of “divisions” in the status bar will change.
- 📱 Check integrity SIM-cards and no scratches on the chip.
- 🏗️ Remove a dense or metal case for a communication test.
- 📍 Move to a window or open space to eliminate wall influences.
- 📡 Make sure that the settings do not include “Flight” mode or power saving of the network.
You also need to pay attention to the overheating of the device, because when you put a lot of work on the processor, the system can artificially limit the power of the transmitter to lower the temperature, and if the phone is hot, let it cool down and check the signal level again.
⚠️ Note: If after removal SIM-The card phone stops seeing the network even with another card, perhaps the problem is in the tray or software failure of the communication module, and not in the "Sim" itself».
📊 How often do you get a signal on Xiaomi?
Only at home/office
Always in town.
Only in the country.
No problem.
Network Types and Preferred Mode
Automatic network type choices don't always work properly, especially in dense urban environments. A smartphone can cling to congested 3G instead of free 4G, which creates the illusion of poor reception. Forced switching to LTE Only or 4G Preferred often solves the problem.
To access advanced settings, you need to use secret codes. Enter ##4636## in the phone book to get into the testing menu. Here, select Phone Information and find "Configure preferred network type."
In the list that opens, select LTE Only or LTE/TD-SCDMA/UMTS. This will cause the modem to ignore weak 2G/3G signals and look for stable 4G. However, remember that in some cases this can lead to a complete lack of voice communication if your carrier does not support VoLTE technology.
What to do if a voice call is missing?
If LTE Only has stopped calling, return settings to LTE/UMTS auto (PRL) mode or make sure that the VoLTE service is activated from your operator.> Remember that different Xiaomi models can react differently to changing modes. On older devices with previous generations of Snapdragon processors, forced 4G can discharge the battery faster. Using the engineering menu to amplify the signal, the powerful tool for fine-tuning the radio module, available on most Mi and Redmi devices. Here you can change the transmission power and sensitivity of the receiver: a forced 4G can lead to a full change of the processor from the input to the user. For MediaTek, try it ##3646633##, a) Qualcomm may require the installation of an application QC Engineer or use ADB-In the menu, go to the Telephony tab -> Network Selecting. The key parameter we're interested in is BandMode, where you can select the specific frequencies that your operator is best at catching in a given area, for example, in rural areas, low frequencies are often more efficient (Band). 3, Band 7, Band 20), Those who have the best penetrating ability. ☑️ BandMode Setup Enter the Engineering Menu Code:Go to Telephony:Select BandMode:Select BandMode:Save and RebootTags: 0 / 1 After selecting the required frequencies, press Set and restart the device. This action will force the modem to scan the airwaves only in the selected range, ignoring the noisy frequencies. Range (Band) Frequency (MHz) Characteristics Where to use Band 3 1800 Speed and coverage Balance City, suburb Band 7 2600 High speed, low coverage Cities Centers, shopping center Band 20 800 Long-haul, low speed Village, cellars, car Band 38 2600 (TDD) Very high speed Stadiums, train stations ⚠️ Warning: Don't turn off all ranges at once. Leave at least one main one (e.g. Band 3 or 7) or the phone will lose the network completely and have to do a reset (APN) Often the problem is not signal strength, but incorrect settings of the access point to the Internet. Operators periodically change the gateways and ports, and the old settings in Android may conflict with the new equipment of the provider. To perform the reset, go to Settings -> SIM-maps and mobile networks -> Access points (APN). Select the one used SIM-map. In the lower right corner of the screen, click on the three menu points and select Reset to Default Settings. Once reset, the phone will automatically download the current settings from the operator. If that doesn't happen, create a new access point manually by entering data from your operator's official website. Pay attention to the APN and APN Type fields - they must match the provider's requirements. Make sure that the access point settings don't have a protocol type restriction. Modern networks are best suited by IPv4/IPv6. This will ensure compatibility with all services and can improve ping in games. Software methods and hidden commands there are a number of hidden radios that allow for abruptions, if the phone to overload and overload. Enter #726633## (not working on all firmware) MIUI) Another effective method is to clear the cache of Google Play services and the system applications that are responsible for communication -> Annexes -> All apps, find Google Play Services and click Clear Cache. This won't delete your data, but update your network configurations. For advanced users, a method of resetting network settings via ADB. Connecting the phone to the PC, execute the command: adb shell svc wifi disable && adb shell svc wifi enable However, for a mobile network, a complete reset of network settings through the menu is more effective: Settings -> Connection and sharing -> Reset Wi-Fi, mobile networks and Bluetooth.This action will remove stored Wi-Fi passwords, but often solves "sticky" issues» EDGE. 🔄 Use the command #726633## to quickly switch modes. 🧹 Clear the cache of system services in case of frequent communication breaks. 📲 Resetting network settings helps when switching between towers. 🛠️ Check for system updates in Settings -> About the phone. Regular firmware updates. MIUI It is also important, as Xiaomi often releases patches that improve modem performance with specific operators.The impact of firmware and regional settings Global and Chinese versions of firmware have different frequency algorithms. (China version) ROM) It may not support some European frequencies (e.g. Band 20), which is critical for country communications. If you overfish your phone or buy a version for China, it may be the reason for the weak signal. Set the region corresponding to your location in the Settings menu -> Additionally -> Region. This will optimize the list of available frequencies and improve the performance GPS In some cases, it helps to disable the Wi-Fi Acceleration or Wi-Fi Assistant function, which automatically switches the phone to the mobile Internet when the router signal is weak, which sometimes works incorrectly, creating connection breaks. You can disable this in the advanced Wi-Fi settings. ⚠️ Warning: Installing global firmware on a Chinese machine (or vice versa) without unlocking the bootloader is impossible and can lead to a “brick” of the device. 💡Changing the region and checking the firmware version are key steps for owners of devices imported from China, as the frequency ranges there are different from those in Europe. FAQ: Frequently Asked Questions Why Xiaomi has a weak signal and another phone has a full signal? This may be due to the design features of the antenna module of a particular Xiaomi or Poco model. Budget models often have less efficient antennas. 3G, It's better, but the Internet is slower. Does the antenna sticker on Xiaomi help? 99% In some cases, it's a marketing ploy. In modern smartphones, antennas are built into a body or a frame, and a sticker on the back cover can't physically amplify the signal. The placebo effect works better here than real technology. How do you test the signal strength in dBm? Go to Settings -> The phone -> All specs -> Status -> SIM-The signal level parameter will show the value in dBm. -50 before -80 dBm is a great signal, below. -110 dBm is a erratic reception zone. Does unlocking the bootloader knock the network out? Unlocking the bootloader alone does not affect the hardware of the antennas, but installing custom recaps or firmware with the wrong modem drivers (RILs) can result in loss of IMEI or unstable communication.