1. Introduction
This manual provides detailed instructions for the setup, operation, and maintenance of your Yoidesu 4G LTE USB Modem. This device functions as a mobile WiFi hotspot, allowing multiple terminals to access the internet via a 4G LTE network. Please read this manual thoroughly before using the product to ensure proper functionality and safety.
2. Package Contents
Verify that all items are present in the package:
- 1 x Portable WiFi Modem (Yoidesu 4G LTE USB Modem)
- 1 x User Manual (This document)
3. Specifications
| Feature | Description |
|---|---|
| Item Type | WiFi Modem |
| Material | ABS |
| Default IP Address | 192.168.100.1 |
| Supported LTE Bands | B1, B3, B7, B8, B20, B38, B40, B41 |
| Maximum Speed | Up to 150Mbps |
| Default SSID | 4G--xxxx (where xxxx is a unique identifier) |
| Default WiFi Key | 1234567890 |
| Card Slot Type | Standard SIM card (not included) |
| Color | White |
4. Setup Instructions
Follow these steps to set up your 4G LTE USB Modem:
- Insert SIM Card: Locate the standard SIM card slot on the modem. Carefully insert your activated standard SIM card into the slot. Ensure the SIM card is correctly oriented as indicated on the device or in the diagram below.

Figure 4.1: Yoidesu 4G LTE USB Modem with SIM card slot visible.
- Connect to Power: Plug the USB modem into a power source. This can be a USB port on a computer, a USB wall adapter, or a power bank. The device will power on automatically.
- Indicator Lights: Observe the indicator lights on the modem. A steady light typically indicates a successful connection to the 4G network. Refer to the troubleshooting section if the light behavior is unexpected.

Figure 4.2: The modem providing WiFi connectivity to multiple devices.
5. Operating Instructions
Once the modem is powered on and connected to the 4G network, you can begin using it as a WiFi hotspot.
5.1 Connecting Devices
- Enable WiFi: On your device (e.g., smartphone, laptop, tablet), enable WiFi.
- Scan for Networks: Search for available WiFi networks. You should see a network named "4G--xxxx" (where xxxx is a unique identifier for your modem).
- Connect: Select the modem's network and enter the default WiFi key: 1234567890.
- Multiple Devices: The modem supports up to 8 connected devices simultaneously, including mobile phones, laptops, computers, and smart TVs.

Figure 5.1: Multiple devices connected to the modem's WiFi network.
5.2 Security Features
The Yoidesu 4G LTE USB Modem utilizes WPA and WPA2 WiFi encryption protocols to secure your network and prevent unauthorized access. It is recommended to change the default WiFi key for enhanced security.

Figure 5.2: Device security features.
5.3 Accessing Modem Settings
To access advanced settings, such as changing the SSID or WiFi password, connect a device to the modem's WiFi network and open a web browser. Enter the default IP address 192.168.100.1 into the address bar. You may be prompted for a username and password (refer to the modem's label or packaging for default credentials, if any).
6. Maintenance
To ensure the longevity and optimal performance of your Yoidesu 4G LTE USB Modem, follow these maintenance guidelines:
- Cleaning: Use a soft, dry cloth to clean the exterior of the modem. Avoid using liquid cleaners or abrasive materials.
- Storage: Store the modem in a cool, dry place away from direct sunlight, extreme temperatures, and humidity when not in use.
- Handling: Handle the device with care. Avoid dropping it or subjecting it to strong impacts.
- Ventilation: Ensure the modem has adequate ventilation during operation to prevent overheating.
7. Troubleshooting
If you encounter issues with your Yoidesu 4G LTE USB Modem, refer to the following common problems and solutions:
| Problem | Possible Cause | Solution |
|---|---|---|
| No internet connection | SIM card not inserted correctly or not activated. No 4G signal. Incorrect WiFi password. | Ensure SIM card is properly inserted and active. Move to an area with better 4G coverage. Verify WiFi password. Restart the modem. |
| Device not powering on | No power supply. Faulty USB port/adapter. | Connect to a different USB power source. Try a different USB port or wall adapter. |
| Slow internet speed | Weak 4G signal. Too many connected devices. Network congestion. | Relocate the modem for better signal. Disconnect unnecessary devices. Contact your mobile network provider. |
| Cannot connect to WiFi network | Incorrect WiFi password. Modem not broadcasting WiFi. | Double-check the WiFi password. Ensure the modem is powered on and indicator lights are normal. Restart the modem and your connecting device. |
8. Warranty and Support
Your Yoidesu 4G LTE USB Modem is covered by a manufacturer's warranty for 90 days from the date of purchase. This warranty covers defects in materials and workmanship under normal use.
For technical support, warranty claims, or further assistance, please contact Yoidesu customer service or visit the official Yoidesu store page:
Yoidesu Store: https://www.amazon.com/stores/Yoidesu/page/9E42D849-CC6F-49C2-A653-8E737C09458E
Please have your product model (B0F8C11LBZ) and purchase information ready when contacting support.