Kircuit Fast 5688W
Kircuit USB-C 15V AC/DC Adapter User Manual
Comprehensive guide for your Kircuit AC/DC Adapter, compatible with Sagemcom Fast 5688W and similar devices.
1. Introduction
This manual provides essential information for the safe and effective use of your Kircuit USB-C 15V AC/DC Adapter. Please read this manual thoroughly before using the product and retain it for future reference.
Safety Information
- Ensure the adapter's voltage and current ratings match your device's requirements.
- Do not expose the adapter to water, moisture, or extreme temperatures.
- Avoid dropping or subjecting the adapter to strong impacts.
- Do not disassemble or attempt to repair the adapter. Refer to qualified personnel for service.
- Unplug the adapter from the power outlet when not in use for extended periods.
- Keep out of reach of children.
2. Product Overview
The Kircuit USB-C 15V AC/DC Adapter is designed to provide reliable power to compatible devices, such as the Sagemcom Fast 5688W T-Mobile 5G Wi-Fi Home Mobile Internet Gateway Router. It converts standard AC power from wall outlets into the necessary DC power for your device.

Figure 2.1: Kircuit USB-C 15V AC/DC Adapter. This image shows the black rectangular adapter unit with its integrated USB-C cable, and a separate AC power cord with a two-prong plug and a figure-8 connector.
Key Features
- Wide Input Voltage: Supports 100-240VAC 50/60Hz for global compatibility.
- Safety Protections: Equipped with Over Voltage Protection (OVP), Over Current Protection (OCP), and Short Circuit Protection (SCP) to safeguard your devices.
- Compatibility: Specifically designed for Sagemcom Fast 5688W, P/N 253944686, T-Mobile FAST5688W 5G Wi-Fi Home Mobile Internet High Speed Gateway Router, and other devices requiring 15V 2.5A USB-C power.
- USB-C Connector: Features a USB Type C charging port for modern device connectivity.
3. Setup
- Connect the AC Power Cord: Insert the figure-8 connector of the AC power cord firmly into the corresponding port on the Kircuit AC/DC adapter unit.
- Plug into Power Outlet: Insert the two-prong plug of the AC power cord into a standard electrical wall outlet (100-240VAC, 50/60Hz).
- Connect to Device: Plug the USB-C connector from the adapter into the USB-C power input port of your compatible device (e.g., Sagemcom Fast 5688W router).
- Verify Connection: Ensure all connections are secure. Your device should now receive power.
Compatibility Notes
This adapter is compatible with devices requiring 15V DC at 2.5A (37.5W) via a USB-C port. It also supports devices that operate at 9V/2A (18W) and 5V/2A (10W) with a USB-C input, such as Sagemcom models NPD36AUS, NP036AUS, and NPD36AU5. Always check your device's power requirements before connecting.
4. Operating
Once properly set up, the Kircuit AC/DC adapter will continuously supply power to your connected device. There are no user-adjustable settings on the adapter itself. The adapter is designed for continuous operation within its specified voltage and current limits.
- Ensure adequate ventilation around the adapter during operation to prevent overheating.
- If your device has a battery, the adapter will charge it while simultaneously powering the device.
- Disconnect the adapter from the device and power outlet when moving or storing the device.
5. Maintenance
The Kircuit AC/DC adapter requires minimal maintenance to ensure its longevity and optimal performance.
- Cleaning: Disconnect the adapter from all power sources before cleaning. Use a soft, dry cloth to wipe the exterior. Do not use liquid cleaners or aerosols.
- Storage: Store the adapter in a cool, dry place away from direct sunlight and extreme temperatures. Coil the cables loosely to prevent damage.
- Inspection: Periodically inspect the adapter and cables for any signs of damage, such as frayed wires, cracked casing, or bent connectors. If damage is found, discontinue use immediately.
6. Troubleshooting
If you encounter issues with your Kircuit AC/DC adapter, refer to the following common problems and solutions:
| Problem | Possible Cause | Solution |
|---|---|---|
| Device not powering on/charging. | Loose connection, no power from outlet, incompatible device, damaged adapter. |
|
| Adapter feels hot during use. | Normal operation, insufficient ventilation, overloaded. |
|
If the problem persists after trying these solutions, please contact Kircuit customer support.
7. Specifications
| Attribute | Value |
|---|---|
| Brand | Kircuit |
| Model | Fast 5688W |
| Input Voltage | 100-240VAC, 50/60Hz |
| Output Voltage/Current | 15V / 2.5A (37.5W) |
| Also Compatible Output | 9V / 2A (18W), 5V / 2A (10W) |
| Connector Type | USB Type C |
| Special Features | OVP, OCP, SCP Protection |
| Color | Black |
| Manufacturer | Shenzhen Waweis Technology Co., Ltd |
| Compatible Devices | Sagemcom Fast 5688W, P/N 253944686, NPD36AUS, NP036AUS, NPD36AU5 |
8. Warranty & Support
Kircuit products are manufactured to high quality standards. For information regarding warranty coverage and terms, please refer to the product packaging or contact your retailer.
Customer Support
If you have any questions, require technical assistance, or need to report an issue with your Kircuit AC/DC Adapter, please contact Kircuit customer support through the vendor from whom you purchased the product. Please have your product model number and purchase details ready when contacting support.
Ask a question about this manual
Ask about setup, troubleshooting, compatibility, parts, safety, or missing instructions. Manuals+ will review the question and use this page’s manual context to help answer it.