Introduction
This manual provides comprehensive instructions for the setup, operation, maintenance, and troubleshooting of your LG 27MP400-B 27 Inch Full HD (1920 x 1080) IPS Display monitor. Please read this manual thoroughly before using the product to ensure proper and safe operation.

Figure 1: Front view of the LG 27MP400-B monitor.
Package Contents
Verify that all items are present in the product box:
- LG 27MP400-B Monitor
- Power Cord
- HDMI Cable
- Stand Base
- Stand Neck
- User Manual (this document)
Setup Instructions
1. Assembling the Stand
- Carefully place the monitor face down on a soft, clean surface to prevent scratches.
- Attach the stand neck to the monitor's rear panel. Ensure it clicks securely into place.
- Connect the stand base to the stand neck. Tighten any screws if provided.
2. Connecting the Monitor
The LG 27MP400-B monitor supports HDMI and D-Sub (VGA) connections.

Figure 2: Rear view of the monitor with input ports.
- HDMI Connection: Connect one end of the provided HDMI cable to the HDMI port on your computer's graphics card and the other end to the HDMI port on the monitor.
- D-Sub (VGA) Connection: Connect a D-Sub cable (not included) to the D-Sub port on your computer and the D-Sub port on the monitor.
- Power Connection: Connect the power cord to the monitor's power input and then plug the other end into a wall outlet.
3. Powering On
Press the power button located on the bottom center of the monitor to turn it on. The power indicator light will illuminate.

Figure 3: Typical desktop setup with the LG monitor.
Operating the Monitor
OnScreen Control Software
The LG OnScreen Control software allows you to easily adjust monitor settings, split the screen, and manage display options directly from your computer. This eliminates the need to use the physical buttons on the monitor.

Figure 4: LG OnScreen Control software interface.
- Download: Visit the official LG website to download the latest version of OnScreen Control for your operating system.
- Installation: Follow the on-screen instructions to install the software.
- Usage: Once installed, you can access various settings such as Picture Mode, Brightness, Contrast, and Display Orientation. The software also allows for screen splitting for enhanced multitasking.
Display Features
- Full HD IPS Display: Experience vibrant colors and wide viewing angles with the 1920 x 1080 Full HD IPS panel.
- 75Hz Refresh Rate: Provides smoother motion and reduced input lag compared to standard 60Hz monitors, beneficial for casual gaming and video playback.
- AMD FreeSync: This technology synchronizes the monitor's refresh rate with your graphics card's frame rate, reducing screen tearing and stuttering during fast-paced gaming. Ensure your graphics card supports AMD FreeSync for this feature to function.
- Reader Mode: Reduces blue light emissions to help alleviate eye strain during long periods of reading or viewing documents. This mode adjusts the screen's color temperature to a warmer tone.
- 3-Side Virtually Borderless Design: The slim bezels on three sides provide an immersive viewing experience and are ideal for multi-monitor setups.
- Wall Mountable: The monitor is compatible with VESA wall mounts (100x100mm) for flexible placement options.

Figure 5: AMD FreeSync technology in action.

Figure 6: Multi-monitor setup showcasing the slim bezels.

Figure 7: Monitor tilt adjustment and wall mount feature.
Maintenance
Proper maintenance ensures the longevity and optimal performance of your monitor.
- Cleaning the Screen: Gently wipe the screen with a soft, lint-free cloth. For stubborn marks, lightly dampen the cloth with water or a specialized screen cleaner. Avoid using harsh chemicals, abrasive materials, or spraying liquid directly onto the screen.
- Cleaning the Casing: Use a soft, dry cloth to wipe the monitor's casing.
- Ventilation: Ensure the ventilation openings on the monitor are not blocked to prevent overheating.
- Power Off When Not in Use: Turn off the monitor when not in use for extended periods to conserve energy and prolong its lifespan.
Troubleshooting
If you encounter issues with your monitor, refer to the following common solutions:
| Problem | Possible Cause | Solution |
|---|---|---|
| No image on screen | Power cable disconnected; Video cable disconnected or loose; Incorrect input source selected. | Check power cable connection; Ensure video cable (HDMI/D-Sub) is securely connected to both monitor and computer; Use the monitor's control button to select the correct input source. |
| Image is blurry or distorted | Incorrect resolution setting; Video cable issue. | Set the display resolution to 1920 x 1080 (Full HD) in your computer's display settings; Try a different video cable. |
| No sound (if using HDMI audio) | Monitor volume too low; Incorrect audio output device selected on computer. | Adjust monitor volume via OnScreen Control or monitor menu; Select the monitor as the default audio output device in your computer's sound settings. |
| Screen tearing or stuttering (during gaming) | AMD FreeSync not enabled or compatible. | Ensure AMD FreeSync is enabled in your graphics card settings and on the monitor (if applicable); Verify your graphics card supports FreeSync. |
If the problem persists after trying these solutions, please contact LG customer support.
Specifications
| Feature | Detail |
|---|---|
| Brand | LG |
| Model Number | 27MP400-B |
| Screen Size | 27 Inches |
| Panel Type | IPS |
| Resolution | 1920 x 1080 (Full HD) |
| Aspect Ratio | 16:9 |
| Refresh Rate | 75Hz |
| AMD FreeSync | Yes |
| Connectivity | HDMI, D-Sub (VGA) |
| Dimensions (WxHxD) | 24.1 x 17.9 x 7.5 inches (with stand) |
| Weight | 7.5 pounds (with stand) |
| Color | Black |
| Mounting | VESA Wall Mountable (100x100mm) |
| Power Voltage | 240 Volts |
| Screen Surface | Matte |

Figure 8: Monitor dimensions.
Support & Resources
For further assistance or detailed information, please refer to the following resources:
- Official User Manual (PDF): Download PDF
- Safety Information (PDF): Download PDF
- LG Customer Support: Visit the official LG website for support, drivers, and FAQs.
LG provides a limited warranty for its products. Please refer to the warranty card included with your product or visit the official LG website for detailed warranty terms and conditions.