Owners of Xiaomi, Redmi and POCO smartphones often face the need to distribute the Internet to a laptop or desktop PC using a mobile network. However, the situation when the USB modem on a Xiaomi phone is not turned on or simply not determined by the system is frighteningly common, this can occur due to the software limitations of the MIUI or HyperOS shell, the lack of drivers in the system or banal hardware incompatibility.
The problem of not connecting can be both physical port damage and hidden Android settings that block the default external devices. In this article, we will take a closer look at all the possible reasons why your USB modem is failing, and provide step-by-step troubleshooting instructions, learn how to properly configure APNs, check modes of operation, and use hidden engineering menus to force the adapter to be activated.
Before you start to manipulate the system, you need to eliminate basic connection errors. Often users forget that not all cables support data transmission, and some carriers block modems outside of special routers. Understanding these nuances will save you time and nerves when you find a solution.
Hardware reasons and equipment compatibility check
The first thing to do is make sure that the problem is not in the hardware. USB Type-C, which require special adapters (OTG) standard-wire USB-If the adapter does not support data transmission or is designed only for charging, the phone will not physically see the connected device.
Power consumption is also important: powerful 4G/LTE modems can consume more power than a smartphone port can deliver in standard mode, especially for older phone models or low battery life, and in such cases, the system can automatically turn off power to the port to protect the motherboard.
Check the list of supported devices, as not all modems work correctly with the architecture of the Snapdragon or MediaTek processors used in Xiaomi.Some whistles require specific drivers that are not built into Android by default.
- 🔌 Make sure that OTG-The adapter is serviceable and supports data transfer, not just charging.
- 🔋 Check the battery level of the smartphone – it is desirable to have more than 20 modems to work%.
- 📱 Try connecting the modem to another Android device to prevent the adapter itself from breaking down.
⚠️ Attention: Use of low-quality cheap products OTG-cables can cause voltage surges and damage to your Xiaomi smartphone’s power controller.
If the physical connection is good, but the indicators on the modem don’t light up or flash differently than usual, try connecting the device through the device. USB-It's an externally powered hub, and it'll help you see if the phone has enough power to run the periphery.
Settings USB-mode and debugging in the Android system
One of the most common reasons why the USB modem on Xiaomi’s phone doesn’t turn on is because of the wrong port mode choice: Android can choose Charge Only mode by default, ignoring data transfer attempts.
To activate the developer menu, go to Settings → About Phone and quickly click 7 times on either MIUI Version or OS Version. After the “You Become a Developer” notification appears, go back to the main settings menu and find the “Additional” or “Extended Settings” section.
Inside the developer menu, we're interested in the option "Default USB Configuration," where you choose RNDIS (USB Ethernet) or USB tethering, which is the mode that allows the smartphone to perceive the connected modem as a network card, rather than as a drive.
☑️ Setting up USB modem
Also, be sure to check if USB Debugging is enabled. Although it is designed for developers, activating it often helps the system to properly initiate drivers for external network adapters.
Problems with drivers and device definition
Unlike Windows, where drivers are installed automatically or manually by the user, Android has a hidden process. If a USB modem is not detected, the system may not have the necessary device profile. Today's Xiaomi smartphones have a built-in driver base for popular Huawei, ZTE and TP-Link models, but rare devices may be left without support.
To check if the phone sees any connection at all, you can use special utilities like USB Device Info or Serial USB Terminal, which will show the VID and PID of the connected device, and if the application shows "No device", then there is a problem at the physics or OTG level.
If the device is displayed but not working, try changing the modem modem. Many modern whistles have a virtual CD-ROM through which you can run a mode switch, even from your phone, if the file manager allows you to open an executable file.
| Type of device | Status in Android | Action required |
|---|---|---|
| CD-ROM Mode | Defined as a storage device | Start the mode switch |
| Modem Mode | Defined as a network card | Set up APN and Access Point |
| Unknown Device | Driver error | Requires ROOT or modem replacement |
| No Device | No reaction. | Check the OTG and cable |
What are VID and PID?
Configuration of the APN access point and operator
Even if the phone technically “sees” the modem and shows a connection to the network, the Internet may not work due to incorrect settings of the access point (APN). Communications operators often require precise settings to access the network, especially when using the network. USB-adapter.
Settings APN Settings are available on the menu → SIM-maps and mobile networks → Choice SIM-map → Access points (APN). You need to create a new access point by entering the data provided by your operator. Usually, it is enough to specify a name (for example, for example, the name of the user, MTS, Beeline, Megafon and APN (web-address).
It's important to choose the hotspot you just created as active. MIUI It can drop the choice to a standard point, ignoring the USB-In such cases, it helps to delete all old profiles. APN and creating new ones from scratch.
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Save a screenshot of the correct APN settings from your carrier’s official website – this will help you quickly restore access in case of a network reset.
Note the type of APN protocol. Most modern 4G/LTE networks need to choose IPv4/IPv6. If only IPv4 is installed, the speed may be limited, or the connection will be permanently broken.
Use of applications for modem management
And with standard Android tools, modem management is not always possible, so specialized applications come to the rescue. PPP Widget 3 (requires) ROOT-rights or simpler analogues such as USB Camera (paradoxically, but sometimes helps in diagnosis) and Serial USB Terminal.
For users without superuser rights, there are aggregator applications that try to emulate the network interface. However, if a USB modem requires complex authorization (PPPoE), root rights are almost impossible to do without, in such cases, the system simply does not know where to send the username and password.
Some applications allow you to forcibly switch the modem from the drive mode to the modem mode, sending special AT-This is true for old whistle models who don't know how to do it automatically.
- 📲 PPP Widget 3 is the most powerful tool for creating PPP-connections, requires a root.
- 🛠 Serial USB Terminal – allows you to send manual commands to the device for diagnosis.
- 🌐 HoTspot – an Internet distribution app that can help reconfigure network interfaces.
Hidden limitations of MIUI and HyperOS
The MIUI shell and the new HyperOS have an aggressive energy-saving system that can block the background processes needed to maintain a USB connection. The system can kill the network management process, considering it an unnecessary energy user.
You need to go to the battery settings, find running applications for network management (or the Android system process), and set a strategy "No restrictions", and turn off traffic savings for system services.
Another issue is the USB Security feature, which can block the connection of unknown devices. Check the security settings and permissions for applications running the network.
⚠️ Note: In some regions versions MIUI function USB Host can be software-disabled at the firmware level, and then only flashing it to Global will help. ROM patchwork.
If nothing works, reset the network settings, which will return all connection parameters to factory values and can eliminate software conflict that interferes with the modem.
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Aggressive MIUI energy saving is a common cause of connection breaks. Be sure to set up exceptions for network services.