How to connect the Xiaomi 4C modem: full instructions with photos and tips

Xiaomi 4C is a compact LTE- modem that allows you to organize high-speed Internet in places where there is no wired connection. Despite the simplicity of the device, its configuration raises questions for many users, from choosing the right USB-port to the configuration of APN. In this article, we will analyze all the steps from unpacking to fine-tuning the network, including solving typical problems.

The Mi Router 4C (modem version) is a combination of router and USB- modem, which means it can be used as a standalone device for Wi-Fi distribution, and paired with the main router to amplify the signal. However, without proper preparation, you risk connection errors or low speed. Next, a step-by-step guide with the nuances of the ZXQPH0002QXXX firmware year.

1.Preparation and preparation for connection

Before you start, make sure you have everything you need. The standard Xiaomi 4C trim includes:

• 📦 The modem itself in black or white case (depending on batch)
• 🔌 Cable USB Type-C → USB-A (length 1 m)
• 📄 Short instructions in Chinese/English
• 🔋 Removable cover for access to the nano-SIM slot

Additionally, you will need: SIM- card with support for 4G/LTE (preferably with unlimited tariff), computer Windows/macOS/Linux or router with USB-port (if you plan to distribute Wi-Fi).Please note: modem Xiaomi 4C is not compatible with SIM- cards micro-SIM or eSIM without an adapter.

Tip: if you connect the modem to the router, make sure that the latter supports the USB Modem Mode function. Popular models with the following option: Xiaomi Mi Router 4A Gigabit, TP-Link Archer C6, ASUS RT-AC51U.

2 Installation of SIM- Card and First Run

Let's start with a physical connection. Follow the instructions.

1. Turn off the modem (if it was on). There is no power button on the case - just disconnect the USB cable.
2. Remove the back cover. Put a nail on it or a plastic card on the Mi logo. The lid is held on the latches, so don't put too much effort into it.
3. Insert the SIM- card into the nano-SIM slot (contacts down). Make sure the card is firmly settled, otherwise the modem will not detect it.
4. Close the cover and connect the modem to the USB- port of the computer or router.

Once connected, the indicator on the case should light up in blue (standby mode) or green (active network connection). If the LED flashes red, this is an error signal (we will discuss the reasons in the troubleshooting section).

3. setup on the computer (Windows/macOS/Linux)

If you connect a modem directly to your PC, the system must automatically install drivers, but 30 percent of the time you need manual configurations — especially on Windows 7/8 or older Linux distributions.

For Windows:

1. Open Device Manager (Win + X → Device Manager).

2.In the Network Adapters section, look for a device called Xiaomi Mobile Broadband or Qualcomm Snapdragon X5 (modem chipset).

3. If a yellow triangle is burning next to the device, download the driver from the official Xiaomi website (select the Mi Router 4C Modem model).

For macOS:

On a Mac, the modem will be defined as the network interface automatically, but for stable operation:

• 🔄 Reboot your computer after you connect.
• 📱 In System Settings → Network, select a new Xiaomi connection and click Apply.
• 🔒 If the internet does not appear, check to see if the firewall connection is blocking (in Security and Security →).

For Linux (Ubuntu/Debian):

At the terminal, execute the commands:

sudo apt update


sudo apt install usb-modeswitch modemmanager

After installation, reconnect the modem. If the connection does not appear, check the logs:

dmesg | grep ttyUSB

💡

On Windows 10/11, a modem can be defined as "Unidentified Device." In this case, download the Qualcomm QMI driver from the chipset manufacturer's website.

4. APN configuration and network settings

Even if the modem is connected, without the correct APN (Access Point Name) settings, the Internet will not work. APN settings depend on your mobile operator. Below are current data for popular providers in Russia and the CIS (2026):

To change the APN settings on your computer:

1. Open Control Panel → Network Control Center → Change the Adapter settings.
2. Find the Xiaomi connection, right-click → Properties.
3. Go to the Dialing Options tab and enter your carrier’s APN data.

For routers, the process is different. For example, on Xiaomi Mi Router 4A, the path will be: Settings → Internet → USB-modem → Setting up APN.

5. Connect to a router for distributing Wi-Fi

If you want to use the Xiaomi 4C as a home network internet source, connect it to the USB- router port.

1. Insert the modem into the USB- port of the router. Use the USB port of the 3.0 (usually blue) for maximum speed.
2. Go to the router’s web interface and enter 192.168.31.1 (for Xiaomi) or 192.168.0.1 (for TP-Link/ASUS) in your browser.
3. Select modem: On Xiaomi: Settings → Internet → Connection Type → USB-modem. On TP-Link: Additional settings → USB-modem → Enable.

Specify the APN settings

Save the settings.

After the restart, the router must distribute the Internet over Wi-Fi. Check the speed at Speedtest. If the speed is below 10 Mbps, try:

• 🔄 Reconnect the modem to another USB- port.
• 📶 Move the modem closer to the window (for better signal 4G).
• 🔧 Update the router’s firmware (instructions in the next section).

💡

When connected to a router, the Xiaomi 4C modem supports up to 32 devices over Wi-Fi at a time, but the real speed depends on the operator’s tariff and network congestion.

6. Firmware Update and Speed Optimization

Factory modem firmware often becomes obsolete, leading to compatibility issues or low speed. The current version of the software (2026) can be downloaded on 4PDA or the official Xiaomi website.

Instructions for updating:

1. Download the archive with firmware (e.g., miwifi_4c_modem_v12.3.4.zip).
2. Connect the modem to the computer.
3. Open My Computer – The modem should be defined as a removable XIAOMI_MOD disk.
4. Copy the firmware file into the root folder of the disk.
5. Turn off and reconnect the modem, and the update will start automatically (the indicator will flash yellow).

After the update:

• 🔄 Reset the modem settings to factory settings (press the Reset button for 10 seconds).
• 📥 Reconfigure APN.
• 📊 Check the speed, it should increase by 15-20%.

Additional tips for increasing speed:

• 🛡️ Disable IPv6 in connection settings (sometimes it conflicts with IPv4).
• 📡 Use an external antenna 4G (connects via port TS-9 on the modem housing).
• ⏱️ Set up Qos on your router if the modem is connected to it (prioritize traffic for video and gaming).

Typical problems and their solutions

Even with the right setup, users are faced with errors.

🔴 Modem is not computer-defined

Causes and solutions:

• 🔌 Problem with USB- port: Try another port or cable.
• 🖥️ No drivers: download them from the Qualcomm website (chipset MDM9207).
• 🔄 Device conflict: Disable other USB- devices and restart your PC.

🟡 The connection is there, but the internet is not working.

Probable reasons:

• ❌ Incorrect settings APN: Check the data from the operator.
• 💰 The account is out of money or the SIM- card is blocked.
• 📵 No coverage 4G: Check the signal level in Device Manager.

🟢 Low Internet speeds

How to improve:

• 📶 Move the modem closer to the window or use the extension cord USB.
• 🔄 Switch to 3G (sometimes more stable 4G in densely populated areas).
• 🛡️ Disable VPN or Proxy on your computer.

⚠️ Warning: If the Xiaomi 4C modem overheats (the body is hot to the touch), turn it off for 10-15 minutes. Overheating can cause automatic shutdown or slowdown. In the long run, use the USB-powered hub.

8. Alternative uses

In addition to standard use, the Xiaomi 4C can be used in non-obvious scenarios:

📱 How to backup internet for a smartphone

If the phone does not have a slot for the second SIM- card, connect the modem to the USB-OTG adapter and configure the USB ethernet in Android settings.

🖥️ For IP- cameras or smart home

The modem can be connected to the Xiaomi Home Gateway or NVR for cameras to provide them with offline Internet, the main thing is to configure a static IP on the local network.

🎮 For online gaming (ping reduction)

If the main Internet is slowing down, connect the modem directly to the PlayStation or Xbox via USB. In the console settings, select Connection via USB-modem.

⚠️ Warning: When using a modem for online gaming, turn off the background download of updates on the console. This will reduce delays (ping) in multiplayer games.

FAQ: Frequent questions about Xiaomi 4C