1. Introduction
The MMD KM40 is a high-performance, compact mechanical keyboard designed for versatility and customization. Featuring a robust CNC aluminum chassis and an O-ring gasket structure, it offers a premium typing experience. With three connection modes (Bluetooth 5.0, 2.4G wireless, and wired Type-C), full hot-swappable switches, and QMK/VIA compatibility, the KM40 is suitable for various applications, from gaming to professional use.
MMD KM40 Tri-mode Mechanical Keyboard showcasing different color options.
2. Package Contents
Please check the package for the following items:
- MMD KM40 Mechanical Keyboard
- Type-A to Type-C Data Cable
- Instruction Manual (this document)
3. Setup
3.1 Charging the Battery
The MMD KM40 is equipped with a 2000mAh lithium battery. Before first use, or if the battery is low, connect the keyboard to a USB power source using the provided Type-A to Type-C data cable. The keyboard can be used while charging.
The keyboard supports tri-mode connection and features a 2000mAh battery.
3.2 Connection Modes
The KM40 supports three connection methods:
- Wired Connection: Connect the keyboard directly to your computer using the Type-C data cable. The keyboard will automatically switch to wired mode.
- 2.4G Wireless Connection:
- Ensure the keyboard is in 2.4G mode (refer to Section 4.1 for mode switching).
- Plug the 2.4G USB receiver into an available USB port on your computer.
- The keyboard should automatically connect.
- Bluetooth 5.0 Connection (3-channel):
- Ensure the keyboard is in Bluetooth mode (refer to Section 4.1 for mode switching).
- On your device (PC, laptop, tablet), go to Bluetooth settings and search for new devices.
- Select 'MMD KM40' from the list of available devices to pair.
- The keyboard supports up to 3 Bluetooth devices. Use specific key combinations (e.g., Fn + 1, Fn + 2, Fn + 3) to switch between paired devices.
4. Operating Instructions
4.1 Power On/Off and Mode Switching
Locate the power switch and mode selector on the keyboard. Use these to turn the keyboard on/off and switch between Wired, 2.4G, and Bluetooth modes.
4.2 Key Customization with QMK/VIA
The MMD KM40 is compatible with QMK/VIA firmware, allowing for extensive key remapping and macro creation. It features 44 customizable keys and supports 10 layers, offering up to 430 practical key values.
QMK/VIA software interface for key customization.
To customize your keyboard:
- Download the VIA software from the official QMK/VIA website.
- Connect your KM40 keyboard to your computer via the wired Type-C connection.
- Launch the VIA software. It should automatically detect your keyboard.
- Use the graphical interface to remap keys, create macros, and configure lighting effects across different layers.
4.3 Layer Switching
The keyboard supports 10 programmable layers for different functions. These layers can be accessed and switched using specific key combinations, typically involving the 'Fn' key. The default layers are:
Visual representation of the 10-layer key-value structure.
- Layer 0: Regular key values
- Layer 1: Games
- Layer 2: Modeling
- Layer 3: Clipping
- Layer 4: Color grading
- Layer 5: Office
- Layer 6: Spreadsheets
- Layer 7: Drawing
- Layer 8: Coding
- Layer 9: Connections and lighting settings
Refer to the VIA software for detailed instructions on how to switch between and configure these layers.
4.4 Lighting Effects
The KM40 features 22 lighting effects and 16.8 million RGB colorful lights. These can be customized through the QMK/VIA software or by using onboard key combinations (e.g., Fn + specific keys for brightness, mode, and color changes).
5. Maintenance
5.1 Cleaning
To clean your keyboard:
- Disconnect the keyboard from all power sources.
- Use a soft, lint-free cloth slightly dampened with water or a mild cleaning solution to wipe the keycaps and chassis.
- For deeper cleaning, you may use a keycap puller to remove keycaps and clean underneath with compressed air.
- Avoid spraying liquids directly onto the keyboard.
5.2 Keycap and Switch Replacement
The MMD KM40 features full hot-swappable switches, allowing you to easily change switches without soldering. The keycaps are 1.7mm thick, 5-sided high-content PBT dye-sublimation.
- Removing Keycaps: Use a keycap puller to gently pull keycaps straight up.
- Removing Switches: Use a switch puller to carefully grip the switch and pull it straight up.
- Installing Switches: Align the pins of the new switch with the holes on the PCB. Gently push the switch down until it clicks into place. Ensure pins are not bent.
- Installing Keycaps: Align the keycap with the switch stem and push down firmly until it is seated.
6. Troubleshooting
- Keyboard not responding:
- Check if the keyboard is powered on.
- Ensure the correct connection mode (Wired, 2.4G, Bluetooth) is selected.
- For wired mode, try a different USB port or cable.
- For 2.4G, ensure the receiver is properly plugged in.
- For Bluetooth, re-pair the device or try a different Bluetooth channel.
- Check battery level and charge if necessary.
- Keys not registering:
- If a specific key is not working, try replacing its switch due to the hot-swap feature.
- Ensure keycaps are properly seated.
- Bluetooth connection issues:
- Ensure your device's Bluetooth is enabled.
- Remove the keyboard from your device's paired list and re-pair it.
- Try connecting to a different Bluetooth channel on the keyboard.
- Lighting not working:
- Check lighting settings via QMK/VIA software.
- Ensure brightness is not set to zero.
7. Specifications
The following table details the specifications of the MMD KM40 keyboard:
| Category | Specification |
|---|---|
| Main Material | GB Standard 6063 Aluminum Pure CNC Engraving |
| Optional Colors | Star Night Black, Starlight Silver, Pomegranate Red, Army Green, Cloud Mist White, Guifei Powder |
| Surface treatment | Anodic oxidation, Electrophoresis |
| Keycap | 1.7mm Thicker 5-Side High-Content PBT Dye-Sublimation |
| Axis | INK White, NP linear switch 45gf, INK Green, INK White |
| Sound package | Poron Cotton + IXPE Switch Pad + PET Sound-Dampening Pad + Switch Base Cotton + Bottom Cotton + Anti-Static Film |
| Structure | O-Ring Structure |
| Connection mode | 5.0 Bluetooth (3-channel) + 2.4G Wireless + Type-C Wired |
| Features | QMK/VIA 44 Keys All Customizable |
| Positioning Plate | Transparent Frosted PC Positioning Plate |
| PCB | Pure White 1.2mm PCB |
| Hot Swap | Full key hot swap |
| Battery | 2000mAh |
| Driver solution | QMK/VIA |
| Lighting | 22 Lighting Effects + 16.8 Million RGB Colorful Lights |
| Accessories | Instruction manual + type-A to Type-C data cable |
| Size | Length 235mm × Width 85mm × Approx. 20-28mm (excluding keycaps) |
| Weight | Approx. 0.62kg |
Detailed configuration list for the MMD-KM40 keyboard.
Internal structure of the MMD KM40, highlighting the O-Ring design and components.
Switch force curves for INK Axis and NP Axis, showing trigger and bottom pressures.
8. User Tips
No specific user tips were found in the provided reviews or Q&A. However, based on common mechanical keyboard usage, consider the following:
- Experiment with Switches: Since the KM40 is hot-swappable, try different switch types to find the feel that best suits your typing or gaming style.
- Utilize QMK/VIA: Take full advantage of the QMK/VIA software to customize keybinds and macros for improved workflow and gaming performance.
- Layer Management: Organize your key layouts across the 10 available layers for different applications (e.g., one layer for gaming, another for programming, and a third for media controls).
9. Support
For further assistance or technical support, please refer to the manufacturer's official website or contact their customer service department. Keep your purchase receipt for any warranty claims.
