Introduction
This manual provides detailed instructions for the safe and efficient operation of your G Keni Retro CD Player Boombox, Model SB3720X. Please read this manual thoroughly before using the device and retain it for future reference.
Package Contents:
- G Keni Retro CD Player Boombox (Model SB3720X)
- User Manual
- Type-C Charging Cable
Important Safety Information
- Do not expose the device to rain or moisture.
- Do not disassemble the device. Refer all servicing to qualified personnel.
- Avoid placing the device near heat sources or in direct sunlight.
- Ensure proper ventilation around the device.
- Use only the provided charging cable.
- Keep out of reach of children.
Product Overview
The G Keni Retro CD Player Boombox is a versatile audio system featuring multiple playback options and a portable design.
Key Features:
- CD, CD-R/RW, MP3, WMA Playback
- Bluetooth 5.0 (Receiver and Transmitter)
- FM Radio (Frequency Range: 76.0 MHz – 108.0 MHz)
- USB Playback (MP3 files, up to 32GB flash drive)
- AUX Input/Output
- Dual HiFi Speakers
- Built-in 3000mAh Rechargeable Battery
- Intuitive Controls and LED Indicators
Component Identification:

This image shows the G Keni Retro CD Player Boombox from a top-down perspective with its transparent lid open. The CD tray is visible, along with the control panel featuring various buttons and a rotary knob.

This image displays the rear panel of the device, highlighting the various input and output ports. From left to right, these include the TF Card Port, USB Port, 3.5mm Earphone Port, AUX Output Connector, and the Type-C 5V/1A charging port.

A detailed view of the control panel, illustrating the layout of the buttons for playback control, repeat functions, mode selection, and the rotary volume knob.
Setup
1. Initial Charging:
Before first use, charge the device for 0.5 to 1 hour for optimal battery performance. Connect the provided Type-C charging cable to the charging port on the back of the unit and to a compatible USB power adapter (not included).
2. Powering On/Off:
Press and hold the power button (usually integrated with the volume knob) for 2 seconds to turn the device on or off.
Operating Instructions
1. Mode Selection:
Press the MODE/BT OUT button to cycle through available modes: CD, AUX, Bluetooth (BT IN), FM Radio, USB, and TF Card.
2. CD Playback:
- Open the clear lid on top of the unit.
- Select the CD mode using the MODE/BT OUT button.
- Place a CD (CD, CD-R/RW, MP3, WMA format) onto the spindle with the label side facing up.
- Rotate the decorative arm to the left to initiate CD playback.
- Use the PLAY/PAUSE, PREVIOUS, and NEXT buttons for control.
- The REPEAT button cycles through repeat modes (e.g., repeat one, repeat all).
- The +10 button allows skipping 10 tracks forward.

This image illustrates the four steps to play a CD: 1. Press and hold the power button for 2 seconds. 2. Select CD mode. 3. Place the CD with the label side up. 4. Rotate the decorative arm to the left to start playback.
3. Bluetooth Operation (BT IN - Receiver Mode):
- Select Bluetooth mode (BT IN) using the MODE/BT OUT button. The LED indicator will flash, indicating pairing mode.
- On your smartphone or other Bluetooth device, search for "G Keni" in the Bluetooth settings.
- Select "G Keni" to pair. Once connected, the LED indicator will stop flashing.
- You can now stream audio from your device to the boombox.

This image depicts the Bluetooth Receiver function, showing a smartphone wirelessly connected to the G Keni CD Player, streaming music.
4. Bluetooth Operation (BT OUT - Transmitter Mode):
This feature allows the boombox to transmit audio (from CD, FM, USB, AUX) to Bluetooth headphones or speakers.
- Ensure your Bluetooth headphones/speaker are in pairing mode.
- While in CD, FM, USB, or AUX mode, press and hold the MODE/BT OUT button for 2 seconds. The LED indicator will flash rapidly.
- The boombox will search for and connect to the nearest available Bluetooth receiving device. Once connected, the LED indicator will stop flashing.
- Audio from the selected source will now play through your Bluetooth headphones/speaker.

This image demonstrates the Bluetooth Transmitter function, showing the G Keni CD Player wirelessly sending audio to a pair of Bluetooth headphones.
5. FM Radio Operation:
- Select FM Radio mode using the MODE/BT OUT button.
- Press the PLAY/PAUSE button to initiate an automatic station scan. The device will scan and save available stations.
- Use the PREVIOUS and NEXT buttons to navigate through saved stations.
- For manual tuning, press and hold the PREVIOUS or NEXT buttons.
- The FM radio has a built-in antenna. Signal reception may vary based on location.

This image shows the G Keni CD Player operating in FM radio mode, with visual representations of radio waves and example frequencies (FM90.5, FM106.3, FM88.5) indicating its functionality.
6. USB/TF Card Playback:
- Insert a USB flash drive (up to 32GB, MP3 files) into the USB port or a TF card into the TF card slot.
- Select USB or TF Card mode using the MODE/BT OUT button.
- The device will automatically begin playing MP3 files.
- Use the PLAY/PAUSE, PREVIOUS, and NEXT buttons for control.

This image highlights the USB and TF card input ports on the G Keni CD Player, demonstrating how to connect external storage devices for MP3 playback. A USB flash drive is shown next to the unit.
7. AUX Input/Output:
- AUX Input: Connect an external audio device (e.g., smartphone, MP3 player) to the AUX IN port using a 3.5mm audio cable. Select AUX mode.
- AUX Output: Connect the AUX OUT port to external speakers or headphones using a 3.5mm audio cable.
8. Volume Control:
Rotate the large knob on the front panel to adjust the volume.
Maintenance
- Clean the device with a soft, dry cloth. Do not use liquid cleaners or abrasive materials.
- Keep the CD tray free from dust and debris.
- When not in use for extended periods, store the device in a cool, dry place.
- Avoid dropping the device. The shock-absorbing corners provide some protection, but extreme impacts can cause damage.

This image provides a close-up view of one of the G Keni CD Player's corners, illustrating the shock-absorbing design intended to protect the device from minor impacts.
Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Device does not power on. | Low battery or no power. | Charge the device using the Type-C cable. Ensure the power button is pressed and held for 2 seconds. |
| CD does not play or skips. | CD is dirty, scratched, or inserted incorrectly. Incorrect mode selected. | Clean the CD. Ensure the CD is placed label side up. Select CD mode. Try a different CD. |
| No sound. | Volume is too low. Incorrect mode selected. External headphones/speakers connected. | Increase volume. Verify correct mode. Disconnect external audio devices if using internal speakers. |
| Bluetooth pairing fails (BT IN). | Device not in pairing mode. "G Keni" not selected on source device. | Ensure the boombox is in BT IN mode and flashing. Re-scan and select "G Keni" on your source device. Move devices closer. |
| Bluetooth transmission fails (BT OUT). | Receiving device not in pairing mode. | Ensure your Bluetooth headphones/speaker are in pairing mode. Press and hold MODE/BT OUT for 2 seconds on the boombox to initiate transmission pairing. |
| Poor FM radio reception. | Weak signal in current location. | Relocate the device to an area with better signal reception. |
| USB/TF card not recognized. | Unsupported format or capacity. Card/drive inserted incorrectly. | Ensure the drive is formatted correctly and contains MP3 files. Maximum capacity is 32GB. Reinsert the drive/card. |
Specifications
| Model Number | SB3720X |
| Brand | G Keni |
| Product Dimensions (L x W x H) | 10 x 6 x 5 inches (25.4 x 15.24 x 12.7 cm) |
| Item Weight | 3.3 pounds (1.5 kg) |
| Connectivity Technology | Bluetooth 5.0, USB, AUX |
| Speaker Type | Stereo Dual Speakers |
| Power Source | Battery Powered (Built-in 3000mAh rechargeable battery) |
| Battery Life | Up to 8 hours (full volume), up to 11 hours (half volume) |
| Supported CD Formats | CD, CD-R/RW, MP3, WMA |
| FM Radio Frequency | 76.0 MHz – 108.0 MHz |
| USB/TF Card Support | MP3 files, up to 32GB maximum capacity |

This image provides key specifications including the device dimensions (8.3 inches wide, 6.0 inches deep, 3.4 inches high) and battery performance (up to 8 hours at full volume, up to 11 hours at half volume).
Warranty and Support
For warranty information and technical support, please refer to the contact details provided with your purchase or visit the official G Keni website. Please retain your proof of purchase for warranty claims.
Manufacturer: K&K International Co.,LTD





