The problem of unstable connection or sudden drop in data rates is familiar to many owners of Chinese smartphones. Xiaomi brand devices, including sub-brands Redmi and POCO, often equipped with powerful processors and high-quality screens, but antenna modules can work incorrectly due to software failures or features of regional firmware. A weak signal is not just annoying when watching videos, it can lead to the loss of important messages or interrupt business calls at the most inopportune moment.
Before you bring your gadget to a service center or buy a new router, you should eliminate software errors that are easy to fix yourself. In the operating system Android with the shell MIUI or HyperOS, there are many tools for diagnosing and fine-tuning network settings. Resetting network settings often solves 80% of problems with the “lost” Internet without losing user’s personal data. In this article, we will discuss all effective ways, from simple reboots to working with the engineering menu.
Sometimes it's not the phone itself, but external factors, like dense buildings, thick walls, or congestion in cell towers. Understanding the physics of radio wave propagation will help you position your device indoors correctly, or choose the optimal place to walk if you need an emergency call. Let's start with the basic but critical actions that every user needs to do.
Basic diagnostics and resetting of network settings
The first step should always be to check the physical condition of the SIM card and the correct installation.If you are using old plastic or the SIM has been hand-cut, contact with the pins in the tray can be unstable, causing constant reconnection to the network.
The most effective software solution is to completely reset your network settings, which will not delete your photos, contacts or apps, but will return all settings related to Wi-Fi, Bluetooth and mobile data to factory values. After this procedure, the phone will forget all saved passwords from wireless networks, so they will have to be re-entered, but often this is the only way to remove the software bug.
To reset on modern versions of the MIUI shell, you need to go to the settings menu. The path may vary slightly depending on the Android version, but the logic remains the same: look for the section responsible for connecting and sharing.
⚠️ Note: After resetting your network settings, all stored Wi-Fi passwords will be deleted. Make sure you remember the data to connect to your home network, or ask someone to dictate it from another device.
Follow the following steps:
- 📱 Open Settings and go to Connection and Sharing.
- 🔄 Find Reset Wi-Fi, mobile networks and Bluetooth (usually at the bottom of the screen).
- ⚙️ Click Reset button and confirm the action with unlock code or pattern lock.
- 📡 After restarting, re-enable the mobile Internet and check the signal level.
If the signal indicates no network or constant search after rebooting, the problem may be deeper, and in rare cases, a temporary switch to flight mode for 10-15 seconds helps, which causes the phone modem to re-register with the network of the nearest tower.
Configure the preferred type of network
Modern smartphones tend to automatically connect to the fastest available network, usually 4G or 5G. However, in conditions of weak coverage or high load on the tower, a stable but slow 3G (H+) can be more reliable than constantly jumping LTE. Forced switching of the network type often stabilizes the connection in transport or out of town.
To change this setting, you will need access to a hidden test menu. On Xiaomi phones, this is done via a standard call. Enter the code ##4636##. If the menu does not open automatically, your firmware may block this access, and then you will need to install a third-party application, such as Force LTE Only from the Play Market store.
In the menu that opens, select Phone Information. Find a drop-down list called "Install preferred network type." Here you'll see many combinations.
Decoding of network modes
Recommended settings for different situations:
- 🚀 LTE/WCDMA/GSM (Auto connect – standard mode for the city, provides better speed and compatibility.
- 📉 LTE only – use only if you need a stable Internet connection without calling (for example, for a navigator or modem).
- 🌍 WCDMA only - compulsory 3G, They are rescued in remote villages where 4G Yes, but the signal is intermittent.
⚠️ Attention: Selection of regime"LTE Only may block voice calls on some operators and in some regions because voice is transmitted through the Internet. 2G/3G, not through 4G (If you don't have VoLTE enabled, be careful when choosing this item.
Once you select the right mode, the phone can lose the network for a few seconds, and then reconnect. If you only chose 4G mode and you don't have it, the phone will write "No network." In that case, just return the settings to automatically select.
Optimizing Wi-Fi Connection on Xiaomi
Wireless problems are often not with the provider, but with the settings of the router or smartphone itself. Xiaomi smartphones can analyze Internet speed and automatically switch from Wi-Fi to mobile traffic if the connection becomes poor, a feature called the Wi-Fi Assistant, and sometimes works incorrectly, cutting off communication during short-term ping spikes.
To turn off this feature and make the phone hold on to the router until the last, go to Settings → Wi-Fi. Click on an arrow or three dots in the corner of the screen to open additional settings. Find the Wi-Fi Assistant and turn off the Mobile Internet Switch switch. This is especially true if you have an unlimited rate or unstable home provider.
Another important aspect is signal frequency. Most modern routers operate in two bands: 2.4 GHz and 5 GHz. The 5 GHz band provides high speed but has very low penetration. A single concrete wall can completely kill the signal.
Comparison of frequency ranges:
| Parameter | 2.4 GHz | 5 GHz |
|---|---|---|
| Range of action | High (up to 50 m indoors) | Low (up to 15-20 m) |
| penetrating ability | Good (passes through walls) | Bad (walls jamming signal) |
| Maximum speed | Up to 150-300 Mbps | Up to 800+ Mbit/ |
| Workload | High (neighborhood routers, microwaves) | Low. |
If your phone is far from the router or behind multiple walls, force it to connect to the 2.4 GHz network. Often a 20 Mbps full signal speed is better than 100 Mbps with constant 5 GHz breaks. MAC-Device address in Wi-Fi settings on your phone – sometimes routers block new ones MAC-address, and it is better to set randomization or use a real address.
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Try to change it. DNS-server in the Wi-Fi settings on your phone. Go to your network properties, select Settings IP" ->"Static" and in the field DNS 1 type in 8.8.8.8 (Google) or 1.1.1.1 (Cloudflare) that can speed up page openings.
Work with engineering menu and regional settings
One of the specific problems with Xiaomi devices is the difference between global (Global) and Chinese (CN) firmware versions, as well as differences in regional frequency standards. If you bought a phone designed for the Chinese market or refashioned the device, you may not be able to use some Band frequencies used by your carriers.
In the engineering menu, available under ##4636##, you can not only choose the type of network, but also see what frequencies (Bands) are active. In the Phone Information section, there is a Run Ping Test button that helps diagnose packet loss. However, deep frequency tuning often requires special commands or the use of the MTK Engineering Mode application for MediaTek processors, which are on many Redmi models.
It is important to understand that regional settings in the phone itself (Settings → Additional → Region) affect the list of available frequencies. If you are in Russia, but the phone is in the region of India or China, the phone may ignore some LTE bands that are priority for local operators.
Checklist of checking the settings of the region:
- 🌍 Set the “Russia” region or country of your residence in the basic settings.
- 📡 Check what ranges (B1, B3, B7, B20) Supports your communications provider.
- 📱 Make sure that these ranges are not turned off in the engineering menu (the ticks must stand).
- 🔄 After changing the region, be sure to restart the device.
The change in region also affects system and advertising applications, but in the context of communication, this is a key parameter for the modem to work correctly, and if the signal level increased after the change of region, then the problem was precisely the software frequency restriction.
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The right region in the smartphone settings is not just content localization, but also activation of the necessary radio frequency bands to work with local telecom operators.
Influence of covers, accessories and physical condition
We often forget that the antennas in modern smartphones are located around the perimeter of the body, often in the upper and lower parts of the frame. Using metal covers, magnetic clasp cases or thick protective glasses with metal edging can shield the signal. Metal creates a "Faraday cage" that blocks radio waves.
Remove the cover and check the signal level. If the difference is significant (1-2 division), then the accessory interferes with the antenna. Also note the back cover: if it cracked or was replaced with a non-original, there may be no special stickers inside to improve the signal passage, or the antenna module itself may be damaged on impact.
Another common cause is oxidation of the SIM card or tray contacts. Moisture, sweat, or just time can lead to the formation of micro-oxides that increase resistance and impair reception. Rubbing contacts with alcohol or eraser (very carefully) sometimes works wonders.
⚠️ Warning: Never use metal plates for magnetic car holders on the back cover in the area of the antenna (usually the upper third of the case), this is guaranteed to degrade the quality of communication several times.
If you dropped your phone, you could have left the plume that connects the antenna module to the motherboard, and in those cases, even if the phone is working, the signal would be very weak, and that would require opening the device and checking the connectors, which is best left to a specialist.
Hidden commands and additional utilities
In addition to the standard engineering menu, there are special codes for resetting the radio interface. The command ##72786## (SCRTUPDT) is designed to reset the system update settings, but on some Xiaomi models it also reboots the network stack. We have already considered using the code ##4636##, but it is worth mentioning that there you can see detailed statistics:
Signal strength: -95 dBm
Cell ID: 123456
LTE Band: 7The signal value in dBm (decibel-milliwatt) is a negative number. The closer it is to zero, the better the signal. For example, -60 dBm is a great signal, -90 dBm is normal, and -110 dBm and below is a zone of uncertain reception where the Internet will work intermittently. Monitoring this value in real time helps to find the best point in the apartment to install a modem or make a call.
There are also third-party apps from the Play Market, like Network Signal Guru (which requires root rights for full functionality) or OpenSignal, which let you map coverage and see which tower your phone is connected to, which is useful if you want to understand why there's a signal in one room and not in the other.