Keychron K5 Max Ultra-Slim Wireless Mechanical Keyboard User Manual

1. Introduction

This manual provides detailed instructions for the Keychron K5 Max Ultra-Slim Wireless Custom Mechanical Keyboard. The K5 Max is designed for versatility and performance, offering 3-mode connectivity (2.4 GHz wireless, Bluetooth 5.1, and Type-C wired), QMK/VIA programmability, and a full-size layout with low-profile Gateron Red switches and durable PBT keycaps. It is compatible with macOS, Windows, and Linux operating systems.

2. Package Contents

Verify that all items are present in your package:

• Keychron K5 Max Keyboard
• USB Type-C to Type-C Cable
• USB Type-A to Type-C Adapter
• 2.4 GHz Receiver
• Keycap Puller
• Switch Puller (if hot-swappable version)
• User Manual

Image: The Keychron K5 Max keyboard showcasing its multi-mode connectivity options.

3. Product Overview

3.1 Key Features

• 3-Mode Connectivity: Seamlessly switch between 2.4 GHz wireless, Bluetooth 5.1, and USB Type-C wired connections.
• QMK/VIA Programmability: Customize key assignments, macros, and lighting effects with open-source firmware.
• Ultra-Slim Design: Features low-profile Gateron mechanical switches, making the keyboard significantly thinner than standard mechanical keyboards.
• 100% Layout: Full-size keyboard with 108 keys, including a dedicated number pad.
• PBT Keycaps: Durable, non-shine-through PBT keycaps for a tactile typing experience.
• White Backlight: Adjustable white LED backlighting for visibility in various lighting conditions.
• Acoustic Foam: Integrated IXPE and latex acoustic foams for quieter keystrokes and improved sound profile.
• High Polling Rate: 1000 Hz polling rate in 2.4 GHz wireless and wired modes for responsive input.

Image: The Keychron K5 Max featuring a 108-key full-size layout, including a number pad.

Image: A close-up view highlighting the ultra-slim profile and low-profile Gateron mechanical switches.

4. Setup

4.1 System Switch

Locate the operating system switch on the side of the keyboard. Slide the switch to the appropriate position for your system (Mac/iOS or Win/Android).

Image: The system switch on the side of the keyboard for selecting between Windows/Android and Mac/iOS modes.

4.2 Connectivity Modes

The K5 Max supports three connection modes: 2.4 GHz wireless, Bluetooth, and wired USB Type-C.

4.2.1 2.4 GHz Wireless Connection

1. Locate the 2.4 GHz receiver in the keyboard's storage slot or packaging.
2. Plug the 2.4 GHz receiver into an available USB port on your computer.
3. Slide the connectivity mode switch on the keyboard to the "2.4G" position.
4. The keyboard should automatically connect. If not, press Fn + 4 for 4 seconds to initiate pairing.

4.2.2 Bluetooth Connection

1. Slide the connectivity mode switch on the keyboard to the "BT" position.
2. To enter pairing mode, press and hold Fn + 1 (for Bluetooth device 1), Fn + 2 (for Bluetooth device 2), or Fn + 3 (for Bluetooth device 3) for 4 seconds until the indicator light flashes rapidly.
3. On your device (computer, tablet, or phone), enable Bluetooth and search for "Keychron K5 Max".
4. Select the keyboard to pair. The indicator light will stop flashing upon successful connection.
5. To switch between paired Bluetooth devices, press Fn + 1, Fn + 2, or Fn + 3 briefly.

4.2.3 Wired Connection

1. Connect the USB Type-C cable to the keyboard and your computer.
2. Slide the connectivity mode switch on the keyboard to the "Cable" position.
3. The keyboard will function as a wired device and will charge its internal battery.

5. Operating Instructions

5.1 Backlight Control

The K5 Max features a white LED backlight. Use the following key combinations to control it:

• Fn + Light Key (bulb icon): Cycle through backlight effects.
• Fn + F5: Decrease backlight brightness.
• Fn + F6: Increase backlight brightness.

Image: The Keychron K5 Max keyboard with its white LED backlight active.

5.2 Multimedia Keys

The top row of function keys (F1-F12) can be used as multimedia keys. Press Fn + F-key for multimedia functions. On macOS, these keys typically function as multimedia keys by default, and Fn + F-key accesses the standard F-key function.

• Fn + F7: Previous Track
• Fn + F8: Play/Pause
• Fn + F9: Next Track
• Fn + F10: Mute
• Fn + F11: Volume Down
• Fn + F12: Volume Up

6. QMK/VIA Programmability

The Keychron K5 Max supports QMK/VIA, allowing for extensive customization of key functions, macros, and lighting. VIA is a graphical user interface that simplifies the process of remapping keys.

6.1 Using VIA Software

1. Download the VIA software from the official Keychron website or the VIA GitHub repository.
2. Connect your K5 Max keyboard to your computer using the USB Type-C cable.
3. Launch the VIA application. The software should automatically detect your keyboard.
4. Use the intuitive drag-and-drop interface to remap any key, create macros, or adjust lighting settings across different layers.
5. Changes are applied in real-time to the keyboard.

Image: The VIA software interface, demonstrating how to program and remap keys on the K5 Max.

7. Maintenance

7.1 Cleaning the Keyboard

• Disconnect the keyboard from all power sources before cleaning.
• Use a soft, lint-free cloth slightly dampened with water or a mild cleaning solution to wipe the keycaps and keyboard surface.
• For deeper cleaning, use the provided keycap puller to remove keycaps and clean underneath with compressed air or a small brush.
• Avoid using harsh chemicals, abrasives, or solvents, as these can damage the keyboard's finish or keycap legends.

7.2 Battery Care

• The keyboard contains a rechargeable Lithium Polymer battery.
• Charge the keyboard using the provided USB Type-C cable connected to a computer or a standard USB power adapter (5V).
• Avoid exposing the keyboard to extreme temperatures, as this can affect battery life and performance.
• If storing the keyboard for an extended period, charge it to approximately 50% to prolong battery health.

8. Troubleshooting

8.1 Keyboard Not Responding

• Check Connectivity: Ensure the mode switch is set correctly (2.4G, BT, or Cable) and the keyboard is properly connected or paired.
• Battery Level: Connect the keyboard via USB-C cable to charge it. A low battery can cause connectivity issues.
• Restart: Turn the keyboard off and then on again.
• Try Wired Mode: If wireless modes fail, connect the keyboard directly via USB-C cable to rule out wireless interference or battery issues.

8.2 Bluetooth Connection Issues

• Re-pair: Remove "Keychron K5 Max" from your device's Bluetooth list and re-pair it following the instructions in Section 4.2.2.
• Interference: Move closer to your device or away from other wireless devices that might cause interference.
• Device Limit: Ensure you are not trying to connect to more than 3 Bluetooth devices simultaneously.

8.3 Keys Not Registering or Double Inputs

• Clean Switches: Dust or debris under the keycap or switch can cause issues. Use compressed air to clean around the affected switch.
• Firmware Update: Check the Keychron website for any available firmware updates for the K5 Max, as these often address known issues.
• Switch Replacement (if hot-swappable): If your K5 Max is the hot-swappable version, a faulty switch can be replaced using a switch puller.

9. Specifications

10. Warranty and Support

For warranty information and technical support, please refer to the official Keychron website or contact Keychron customer service directly. Details regarding warranty periods and service procedures are typically provided with your purchase documentation or on the manufacturer's support pages.

Online Resources:

• Official Keychron Website: www.keychron.com
• QMK/VIA Software & Firmware: Refer to the Keychron support section on their website.