1. Introduction
This manual provides essential information for the safe and efficient use of your LG K51 Unlocked Smartphone. The LG K51 is designed to offer a comprehensive mobile experience with features such as a 6.5-inch HD+ FullVision display and an easy-to-use triple camera system. Please read this manual thoroughly before operating your device.
2. What's in the Box
Upon unboxing your LG K51, please ensure all the following items are present:
- LG K51 Unlocked Smartphone
- SIM Ejector Tool
- Travel Adapter (Charger)
- USB Cable
3. Device Overview
Familiarize yourself with the physical components of your LG K51 smartphone.

Figure 3.1: Front view of the LG K51 smartphone, showcasing the 6.5-inch FullVision display and front camera. The screen displays the time and date with a 'Swipe to unlock' prompt.

Figure 3.2: Rear view of the LG K51 smartphone, highlighting the triple camera system, fingerprint sensor, and LG logo.
3.1 Key Components
- Front Camera: Located at the top of the display for selfies and video calls.
- Display: 6.5-inch HD+ FullVision screen.
- Volume Buttons: On the left side, for adjusting audio levels.
- Power/Lock Button: On the right side, for turning the device on/off or locking/unlocking the screen.
- Triple Rear Camera: Consists of a 13MP PDAF Standard Angle, 5MP Super Wide 115°, and 2MP Depth camera.
- Fingerprint Sensor: Located on the rear for secure unlocking and authentication.
- USB-C Port: At the bottom for charging and data transfer.
- 3.5mm Audio Jack: At the bottom for headphones.
4. Setup
4.1 Inserting the SIM Card and microSD Card
- Locate the SIM/microSD card tray on the side of your device.
- Insert the SIM ejector tool into the small hole next to the tray to open it.
- Place your Nano-SIM card into the designated slot with the gold contacts facing down.
- If using a microSD card for expanded storage, place it into its designated slot.
- Carefully push the tray back into the device until it clicks into place.
4.2 Charging the Battery
Before first use, fully charge the device battery. Connect the USB cable to the USB-C port on your phone and the other end to the travel adapter. Plug the adapter into a power outlet. The battery icon on the screen will indicate charging status.
4.3 Powering On/Off
- To Power On: Press and hold the Power/Lock button on the right side until the LG logo appears.
- To Power Off: Press and hold the Power/Lock button, then tap 'Power off' on the screen.
- To Restart: Press and hold the Power/Lock button, then tap 'Restart' on the screen.
4.4 Initial Setup
Upon first power-on, follow the on-screen prompts to set up your device. This includes selecting your language, connecting to Wi-Fi, setting up your Google account, and configuring security features like fingerprint unlock.
5. Operating Your Device
5.1 Basic Navigation
- Touch: Tap items on the screen to select them.
- Swipe: Drag your finger across the screen to scroll or move between screens.
- Pinch: Use two fingers to zoom in or out on photos and web pages.
- Home Screen: Press the Home button (virtual button at the bottom of the screen) to return to the main home screen.
5.2 Making Calls and Sending Messages
- Calls: Open the Phone app, enter the number, and tap the call icon.
- Messages: Open the Messages app, tap the new message icon, enter the recipient and your message, then send.
5.3 Camera Usage
The LG K51 features a versatile triple camera system:
- Standard Angle: For everyday photos.
- Super Wide Angle (115°): Ideal for landscapes and group shots.
- Depth Camera: Used for Bokeh effect portraits, blurring the background for a professional look.
To use the camera, open the Camera app from your home screen or app drawer. Tap the shutter button to take a photo. Switch between lenses by tapping the icons on the screen.
5.4 Connectivity
- Wi-Fi: Go to Settings > Network & internet > Wi-Fi to connect to available wireless networks.
- Bluetooth: Go to Settings > Connected devices > Bluetooth to pair with Bluetooth accessories like headphones or speakers.
- Mobile Data: Ensure mobile data is enabled in Settings > Network & internet > Mobile network for internet access via your cellular provider.
6. Maintenance
6.1 Battery Care
- Avoid exposing the device to extreme temperatures.
- For optimal battery longevity, avoid frequently discharging the battery completely.
- Use only the LG-approved charger and cable provided with your device.
6.2 Software Updates
Regularly check for software updates to ensure your device has the latest features and security enhancements. Go to Settings > System > Update center > Software update.
6.3 Cleaning Your Device
Use a soft, lint-free cloth to clean the screen and body of your phone. Avoid using harsh chemicals or abrasive materials.
7. Troubleshooting
If you encounter issues with your LG K51, try the following common solutions:
- Device is unresponsive or frozen: Press and hold the Power/Lock button for approximately 10 seconds to force a restart.
- Cannot connect to Wi-Fi: Ensure Wi-Fi is enabled in settings. Try restarting your router and the phone.
- Poor battery life: Check background app usage in settings. Reduce screen brightness. Disable unnecessary features like GPS or Bluetooth when not in use.
- Apps crashing: Clear the cache for the problematic app (Settings > Apps & notifications > App info > [App Name] > Storage & cache > Clear cache). If the issue persists, try reinstalling the app.
- No network signal: Ensure your SIM card is correctly inserted. Check if airplane mode is off. Contact your service provider if the issue persists.
8. Specifications
| Feature | Detail |
|---|---|
| Model Number | LMK500QM7 |
| Operating System | Android 10.0 |
| Display Size | 6.5 Inches |
| Resolution | 1560 x 720 |
| RAM | 3 GB |
| Internal Storage | 32 GB |
| Rear Camera | 13MP (Standard), 5MP (Super Wide 115°), 2MP (Depth) |
| Battery Capacity | 4000 mAh |
| CPU Speed | 2 GHz |
| Connectivity | Bluetooth, USB, Wi-Fi, 4G |
| Audio Jack | 3.5 mm |
| Dimensions | 2 x 4 x 7 inches |
| Item Weight | 12 ounces |
9. Warranty and Support
Your LG K51 Unlocked Smartphone is covered by a manufacturer's warranty. For detailed warranty information, please refer to the warranty card included in your product packaging or visit the official LG website. For technical support, software updates, and additional resources, please visit the LG support website or contact LG customer service.
Note: Warranty terms and conditions may vary by region and retailer.