1. Product Overview
The Lytmi Fantasy 3 TV Backlight Kit enhances your viewing experience by synchronizing ambient lighting with your screen content. It features an HDMI 2.1 sync box supporting high resolutions and a high-density LED strip for vibrant, accurate color reproduction.

Image: The Lytmi Fantasy 3 TV Backlight Kit providing immersive ambient lighting during a gaming session.
Package Contents
Verify that all components are present in your package:
- Neo 3 Sync Box
- LED Light Strip
- HDMI Cable
- AC Power Adapter
- Fixing Clips
- User Manual (this document)

Image: Contents of the Lytmi Fantasy 3 TV Backlight Kit package.
2. Setup Guide
2.1 App Installation and Initial Setup
Before connecting the hardware, download and set up the Lytmi Home App on your mobile device.
- Search for "Lytmi Home" in your device's app store and install it.
- Ensure your mobile device's Wi-Fi, Bluetooth, and location services are enabled.
- Open the Lytmi Home App and follow the on-screen prompts to create an account or log in.
2.2 Hardware Connection
Follow these steps to connect the components:
- Prepare the TV Surface: Clean the back of your TV thoroughly to ensure proper adhesion of the LED strip.
- Attach the LED Strip: Carefully peel the adhesive backing from the LED strip and firmly press it along the edges of the back of your TV. Use the provided fixing clips for additional security, especially around corners. Ensure the strip is positioned correctly for full corner mapping.
- Connect LED Strip to Sync Box: Plug the LED strip connector into the designated "LED STRIP" port on the Neo 3 Sync Box.
- Connect Power: Plug the AC power adapter into the "POWER" port on the sync box, then into a wall outlet.
- Connect to TV: Use an HDMI cable to connect the "TV" output port on the sync box to an HDMI input port on your television.
- Connect Input Devices: Connect your HDMI source devices (e.g., gaming console, streaming box, PC) to the HDMI 1-4 input ports on the sync box. The sync box supports HDMI 2.1 for high-resolution pass-through.

Image: Connection diagram for the Lytmi Fantasy 3 TV Backlight Kit.
2.3 Device Pairing and Verification
After physical connections, pair the sync box with the app and verify functionality.
- Open the Lytmi Home App. The app should automatically detect the Neo 3 Sync Box. If not, tap "Add Device" and select "Neo 3".
- Follow the app's instructions to complete the pairing process, including connecting to your Wi-Fi network.
- Check LED Strip: Use the app to change the LED strip color (e.g., to blue or red) to confirm it is functioning correctly.
- Check Sync Box: Verify that the image and sound from your connected HDMI devices are correctly displayed on your TV through the sync box.
Video: Official Lytmi Fantasy 3 Backlight Kit Installation Guide, demonstrating unboxing, app setup, hardware connections, and initial checks.
3. Operating Modes
The Lytmi Fantasy 3 TV Backlight Kit offers several operating modes to customize your lighting experience.
3.1 Sync Mode
In Sync Mode, the LED backlight dynamically matches the colors displayed on your TV screen in real-time. This creates an immersive visual extension of your content.
- Supports 8K 60Hz and 4K 120Hz for ultra-immersive viewing, ideal for gaming and high-resolution video.
- Features an accurate lighting algorithm that picks and combines colors to sync precisely, even with fast-paced content.
- Full Corners Mapping ensures all four corners of your TV are color-matched for a perfectly synchronized visual experience.

Image: Smart and Accurate Sync in action, providing real-time color matching.
3.2 Music Mode
Music Mode allows the LED lights to react to audio, creating a dynamic light show that pulsates and changes with the rhythm and intensity of your music.
3.3 Scene Mode
Choose from a variety of pre-set lighting scenes or customize your own to create specific moods and atmospheres in your room, independent of screen content.
3.4 Control Methods
The Lytmi Fantasy 3 TV Backlight Kit can be controlled via:
- Lytmi Home App: Provides comprehensive control over modes, colors, brightness, and custom scenes.
- Voice Control: Compatible with Alexa and Google Assistant for hands-free operation.
4. Maintenance
To ensure the longevity and optimal performance of your Lytmi Fantasy 3 TV Backlight Kit, follow these general maintenance guidelines:
- Cleaning: Regularly wipe the LED strip and sync box with a dry, soft cloth to remove dust. Avoid using liquid cleaners directly on the components.
- Cable Management: Ensure all cables are neatly organized and not under strain to prevent damage.
- Environmental Conditions: Operate the device within recommended temperature and humidity ranges. Avoid exposing it to extreme heat, cold, or moisture.
5. Troubleshooting
If you encounter issues with your Lytmi Fantasy 3 TV Backlight Kit, consider the following basic troubleshooting steps:
- No Power/Lights Off: Check all power connections. Ensure the power adapter is securely plugged into the sync box and the wall outlet.
- Lights Not Syncing: Verify that your HDMI source device is connected to an input port on the sync box and that the sync box is correctly connected to your TV's HDMI input. Ensure Sync Mode is activated in the Lytmi Home App.
- Incorrect Colors/Dim Lights: Check the LED strip installation for any kinks or damage. Ensure the strip is clean. Adjust brightness and color settings in the Lytmi Home App.
- App Connectivity Issues: Ensure your mobile device's Wi-Fi, Bluetooth, and location services are active. Restart the Lytmi Home App or your mobile device. If issues persist, try re-pairing the device.
- No Image/Sound from HDMI Device: Confirm that the HDMI cables are securely connected. Try connecting the HDMI source directly to the TV to rule out cable or source issues.
For more complex issues or persistent problems, please refer to the support section.
6. Specifications
| Feature | Detail |
|---|---|
| Brand | Lytmi |
| Model Number | LDD21 |
| Color | RGB (Red, Green, Blue) |
| Light Source Type | LED |
| Power Source | DC |
| Voltage | 12 Volts (DC) |
| Wattage | 36 watts |
| Connectivity | Wi-Fi, Bluetooth |
| Control Method | App, Voice Control (Alexa, Google Assistant) |
| HDMI Support | HDMI 2.1 (8K@60Hz, 4K@120Hz) |
| LED Density | 72 LEDs per meter (252 Built-in LEDs total for 55-60 inch TV) |
| Material | Polyvinyl Chloride |
| Item Weight | 1.98 pounds |
| UPC | 714955976449 |
7. Warranty and Support
7.1 Warranty Information
The manufacturer's warranty for this product is not specified in the provided information. Please refer to your purchase documentation or contact Lytmi customer support for detailed warranty terms.
7.2 Customer Support
If you have any questions, require technical assistance, or need to report an issue, please contact Lytmi customer support:
- Email: support@lytmi.co
Lytmi provides 24/7 customer service and aims to provide a satisfactory solution as quickly as possible.





