Keychron K4 Bluetooth Wireless Mechanical Keyboard User Manual

Product Overview

The Keychron K4 is a compact 100-key (96% layout) mechanical keyboard designed for versatility and productivity. It features RGB backlighting, hot-swappable switches, and an aluminum frame. The keyboard supports both Bluetooth wireless and USB Type-C wired connections, offering broad compatibility with various operating systems.

Image: Keychron K4 mechanical keyboard featuring a 96% layout with 100 keys and a durable aluminum frame, shown on a desk setup.

Setup

1. Package Contents

Before you begin, ensure all items are present:

• Keychron K4 Mechanical Keyboard
• USB Type-C Cable
• Extra Keycaps for Windows and Mac
• Keycap Puller
• Switch Puller (for hot-swappable versions)

2. Charging the Keyboard

The keyboard is equipped with a 4000 mAh battery. For optimal performance, fully charge the keyboard before first use.

1. Connect the provided USB Type-C cable to the keyboard's USB-C port.
2. Connect the other end of the cable to a USB power source (e.g., computer USB port, wall adapter).
3. The charging indicator light will show the charging status. A full charge can provide up to 72 hours of typing or 7 days of normal use (8 hours/day).

Image: Top-down view of the Keychron K4 keyboard, highlighting its 4000 mAh battery capacity.

3. Connecting the Keyboard

The Keychron K4 supports both Bluetooth wireless and USB Type-C wired connections.

Bluetooth Connection:

1. Locate the mode switch on the side of the keyboard and set it to Bluetooth.
2. Press and hold the Fn + 1 (or Fn + 2, Fn + 3) key combination for 4 seconds to enter pairing mode. The indicator light will flash rapidly.
3. On your device (computer, smartphone, tablet), enable Bluetooth and search for "Keychron K4".
4. Select "Keychron K4" to pair. The indicator light will stop flashing upon successful connection.
5. To switch between paired devices, press Fn + 1, Fn + 2, or Fn + 3.

Wired Connection:

1. Locate the mode switch on the side of the keyboard and set it to Cable.
2. Connect the provided USB Type-C cable from the keyboard to your device's USB port.
3. The keyboard will automatically be recognized and function as a wired keyboard.

Image: Overhead view of the Keychron K4 keyboard, illustrating its dual connectivity modes: wireless (Bluetooth) and wired (USB-C).

4. Operating System Compatibility

The Keychron K4 is compatible with both macOS and Windows operating systems. Use the OS switch located on the side of the keyboard to select the appropriate mode for your system.

• Set the switch to Mac for macOS devices.
• Set the switch to Windows for Windows devices.

Extra keycaps for both operating systems are included to customize the keyboard layout as needed.

Image: The Keychron K4 keyboard displayed with icons indicating compatibility with both Mac and Windows operating systems.

Operating Instructions

1. RGB Backlighting Control

The Keychron K4 features over 15 types of RGB backlight options. You can cycle through different lighting effects and adjust brightness.

• Press the light bulb key (usually located on the top right) to cycle through different RGB lighting effects.
• To adjust brightness, use the dedicated brightness keys (if available) or a function key combination (refer to the keyboard's keycap legends for specific shortcuts).
• A static white light mode is also available.

Image: Close-up view of the Keychron K4 keyboard keys illuminated with various RGB backlight colors.

2. Function Keys and Multimedia Controls

The K4 includes a full row of function keys (F1-F12) and multimedia controls. These functions are typically accessed by holding the Fn key and pressing the corresponding function key.

• Fn + F1/F2: Decrease/Increase screen brightness (Mac).
• Fn + F3/F4: Mission Control/Launchpad (Mac).
• Fn + F7/F8/F9: Previous Track/Play-Pause/Next Track.
• Fn + F10/F11/F12: Mute/Volume Down/Volume Up.
• Fn + Light Bulb Key: Cycle RGB lighting effects.

Note: Specific key functions may vary slightly based on the operating system selected.

3. Ergonomic Design

The Keychron K4 features an inclined bottom frame and adjustable feet, allowing users to set the keyboard at a comfortable typing angle (6° or 9°). This design promotes a more natural wrist position, reducing strain during extended use.

Image: Side profile of the Keychron K4 keyboard, illustrating its OEM profile curved keycaps and adjustable feet for 6-degree and 9-degree typing angles.

Maintenance

1. Cleaning the Keyboard

Regular cleaning helps maintain the keyboard's performance and appearance.

• Disconnect the keyboard from your device before cleaning.
• Use a can of compressed air to remove dust and debris from between the keycaps.
• Wipe the keycaps and frame with a soft, slightly damp, lint-free cloth. Avoid excessive moisture.
• Do not use harsh chemicals or abrasive materials.

2. Hot-Swappable Switches

The Keychron K4 features hot-swappable switches, allowing you to change switches without soldering. This model comes with Gateron Red switches.

1. Ensure the keyboard is disconnected from power.
2. Use the provided keycap puller to carefully remove the desired keycap.
3. Use the provided switch puller to gently grasp the switch and pull it straight up.
4. Align the pins of the new switch with the holes on the PCB and press it firmly into place until it clicks. Ensure the pins are not bent.
5. Replace the keycap.

Image: Close-up view of the Keychron K4 keyboard demonstrating hot-swappable switches, with Gateron Red, Brown, and Blue switches removed and ready for replacement.

Troubleshooting

1. Keyboard Not Connecting via Bluetooth

• Ensure the keyboard's mode switch is set to Bluetooth.
• Verify the keyboard battery has sufficient charge.
• Try re-entering pairing mode by holding Fn + 1 (or Fn + 2, Fn + 3) for 4 seconds.
• On your device, remove "Keychron K4" from the list of paired Bluetooth devices and attempt to pair again.
• Restart both the keyboard and your device.

2. Keyboard Not Responding in Wired Mode

• Ensure the keyboard's mode switch is set to Cable.
• Check that the USB Type-C cable is securely connected to both the keyboard and your device.
• Try using a different USB port on your device or a different USB Type-C cable.

3. Backlighting Not Working or Incorrect

• Ensure the keyboard battery has sufficient charge, as backlighting consumes power.
• Press the light bulb key to cycle through lighting modes and ensure it's not set to off.
• Adjust brightness settings using the appropriate function key combinations.

4. Keys Not Registering or Double-Typing

• For hot-swappable models, ensure the switch is fully seated in its socket. Carefully remove and re-insert the switch.
• Clean around the affected key to remove any debris that might be interfering with the switch mechanism.
• If the issue persists, consider replacing the switch with a new one.

Specifications

Gateron G Pro Mechanical Switch Features

Image: A table detailing the specifications of Gateron G Pro mechanical switches, including operating force, pre-travel, travel distance, behavior, pre-lubrication, sound level, and recommended use for Red, Blue, and Brown switch types.

Warranty and Support

Keychron products are designed for durability and performance. For warranty information, please refer to the official Keychron website or contact their customer support directly. Keep your purchase receipt for warranty claims.

For technical support, troubleshooting assistance, or further inquiries, please visit the Keychron support page or contact their customer service team. Contact details are typically available on the official Keychron website.

Official Website: www.keychron.com