Xiaomi smartphones are famous for their functionality and affordable price, but owners often face the whims of embedded modems. The situation when the indicator shows the full signal level, and the pages do not load or calls are broken, is familiar to many, this can be due to software failures of the MIUI shell or HyperOS, and the physical features of the antenna module.
Before you bring your device to the service, you should try a set of software optimization methods. The quality of communication depends on the correct settings of frequency bands and priority networks. In this article, we will discuss effective ways to stabilize the connection that will help you return to comfortable use of mobile Internet and voice communication.
Diagnostics of the current situation and operator selection
The first step is always to make an objective assessment of the situation. Often the problem is not with the smartphone itself, but with the coverage of your mobile operator in a particular location, with monolithic concrete buildings, basements and remote areas creating “dead zones” where even flagship models are unstable.
Check how you're behaving. SIM-If the second phone is also missing or extremely weak, the problem is on the provider's side, and Xiaomi's software settings won't help, but if everything is flying in the next phone and your phone is barely breathing, then it's time to dig deeper.
Notice the current communication standard: Switching between 2G, 3G and 4G/5G can be incorrect, causing the phone to “cling” to a weak signal from the far tower instead of switching to a more stable, but nearer one.
It is also important to consider the physical condition. SIM-Old cards that have been cut with scissors or used for more than 5 years can oxidize or have micro-damage to the contacts, resulting in periodic connection breaks and network logging errors.
Basic network settings and parameter reset
The simplest and most often ignored method is a complete reset of network settings, which will not delete your personal data, photos or contacts, but will return all modem and Wi-Fi settings to factory values, which helps eliminate software conflicts that arose after the system update.
To do this, go to Settings → Connection and Sharing → Reset Wi-Fi, mobile networks and Bluetooth. After that, the device will reboot, and you will need to re-enter passwords from wireless networks, often solving the problem of sticking the modem at certain frequencies.
It is important to prioritize the type of network correctly. If you are in a zone of uncertain 4G reception, the phone can constantly try to catch it, losing stable 3G. Forced switching can give a temporary but important increase in stability.
☑️ Checklist of basic settings
Remember the simple but effective procedure of restarting, which clears RAM and restarts all system services, including the radio, and if you haven't turned your phone off for weeks, a build-up of time errors is likely.
Using an engineering menu to amplify the signal
One of the most powerful hidden features of MIUI-based Android is the engineering menu, which allows the user to manually control the parameters of the radio module, where you can turn off the extra frequency bands that the phone is trying to scan, thereby speeding up the search for an available tower.
To enter the menu, dial the code ##4636## in the phone book. If the code is not working, your firmware version may have blocked this access and you will need to install a special activator application or use it. ADB-In the menu that opens, select "Phone Information».
⚠️ Warning: Be extremely careful when changing settings in the engineering menu.Switching off critical bands can lead to complete loss of communication, and it will be difficult to get everything back without resetting the settings.
Find the option "Install preferred network type." Here you can select a mode, for example, LTE Only (4G only). This is useful if you want to use the phone as a modem in the zone of 4G confident reception, but the phone is constantly jumping to 3G. However, remember that in LTE Only mode, incoming voice calls may not pass if the operator does not support VoLTE technology.
Also on this menu you can see the actual signal power in dBm. -80 dBm is considered excellent, while -110 dBm and below indicates a critically weak signal, where the speed will be minimal.
What to do if the engineering menu code doesn’t work?
Adjusting Access Points (APNs) to speed up the internet
Often, low Internet speeds with a good signal level are due to incorrect APN (Access Point Name) settings. Operators automatically send these settings, but they may not be optimized for a specific region or tariff type.
To check or change settings, go to Settings path → SIM-maps and mobile networks → Choose yours. SIM → Access points (APN). Click on the "New Access Point" button or edit an existing one. Pay special attention to the "Name" and "Access Point" fields» (APN) — They must strictly match the data on your operator’s website.
In some cases, changing the type of APN helps. The default is default,supl. You can try adding dun (for the distribution of the Internet) or changing the protocol to IPv4/IPv6 if you only have one of them, which can remove the speed limits that sometimes arise when tunneling traffic.
| Parameter | Recommended value | Description |
|---|---|---|
| Name. | Any (e.g. MTS Fast) | Profile name for convenience |
| APN | internet.mts.ru | Gateway address (depending on operator) |
| Type APN | default,supl | Types of supported connections |
| Protocol | IPv4/IPv6 | Preferred network protocol |
After making changes, be sure to save the profile (usually through a three-point menu) and activate it. It is not superfluous to turn on and off Flight Mode so that modem re-registers on the network with new parameters.
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Tip: Before you change your APN settings, take a screenshot of the original values. If the new profile doesn't work or the Internet goes down, you can quickly get it back to normal.
Influence of covers and physical factors
We live in the era of digital solutions, but physics has not been canceled. The antennas in Xiaomi smartphones are often located around the perimeter of the case or at the top/bottom of the back cover. The use of metal cases, magnetic clasp cases or dense silicone linings with metallized coating can shield the signal.
If you take off the case and check the signal level, if the difference is significant (for example, there was 1 division, became 3), then the problem is solved by replacing the accessory. Also, the quality of communication is affected by charging: cheap power supplies and cables without shielding create strong electromagnetic interference that “muffle” the antenna.
If you notice that the connection is lost during charging, try changing the cable or power supply to a better, certified one, especially for older chargers that no longer meet current electromagnetic compatibility standards.
Resetting and radical measures
If the program dances with the drum don’t work, the final argument is a complete factory reset, which is guaranteed to remove any system errors, viruses or application conflicts affecting the radio module.
Before this step, make sure to back up your data. Go to Settings → About Phone → Settings Reset → Erase all data. Once reset, the phone will be as new as you can check the network on a clean system without third-party software.
⚠️ WARNING: A full reset will delete all photos, contacts and apps. Make sure you have an up-to-date copy of important data in the cloud or on your computer.
In case even after resetting and flashing (if you have the skills of flashing), the problem persists, it is a hardware malfunction: it can be an unstuck antenna (often after falls), oxidation of the contacts of the antenna module or failure of the radio part itself.
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If resetting and replacement SIM-The cards didn't help, but on another phone. SIM It works perfectly, it's likely that the antenna module or the plume will break down.