Getting Started
What's in the Box:
- LG K40 smartphone
- USB-C charging cable
- Wall charger adapter
- Quick start guide
- SIM ejector tool
Initial Setup Guide
- Insert SIM Card: Use the SIM ejector tool to open the SIM tray and insert your nano-SIM card.
- Insert Memory Card: Optional microSD card can be inserted in the dedicated slot for additional storage.
- Power On: Press and hold the power button until the LG logo appears.
- Language Selection: Choose your preferred language from the available options.
- Connect to Wi-Fi: Select your Wi-Fi network and enter the password to connect.
- Google Account: Sign in with your Google account or create a new one.
- Security Setup: Set up screen lock (pattern, PIN, or password) for device security.
- Final Setup: Complete the remaining setup steps and your device is ready to use.
Specifications
| Model Number | LM-X420QM |
| Display | 5.7-inch HD+ FullVision Display |
| Resolution | 1440 x 720 pixels (18:9 ratio) |
| Processor | MediaTek MT6762 Octa-core 2.0 GHz |
| RAM | 2GB |
| Internal Storage | 32GB (expandable up to 2TB via microSD) |
| Operating System | Android 9.0 Pie |
| Rear Camera | 16MP with LED flash |
| Front Camera | 5MP |
| Battery | 3000mAh (non-removable) |
| Connectivity | 4G LTE, Wi-Fi, Bluetooth 5.0, GPS |
| Dimensions | 153 x 71.9 x 8.3 mm |
| Weight | 170g |
Warranty Information
- Standard Warranty: 1 year limited warranty
- Battery Warranty: 6 months
- Accessories Warranty: 3 months
- Extended Coverage: Optional protection plans available
For warranty service, contact LG Customer Service at 1-800-243-0000 or visit LG.com
Key Features
FullVision Display
5.7-inch HD+ FullVision display with 18:9 aspect ratio provides an immersive viewing experience with minimal bezels.
DTS:X 3D Surround Sound
Enjoy immersive 3D surround sound experience with DTS:X technology for enhanced audio quality through headphones.
16MP Rear Camera
Capture clear and detailed photos with the 16MP rear camera featuring PDAF and LED flash for low-light conditions.
Google Assistant
Built-in Google Assistant allows voice commands for tasks, information, and smart home control with just your voice.
Fingerprint Sensor
Convenient rear-mounted fingerprint sensor provides secure and quick device unlocking and app authentication.
Military Standard Durability
MIL-STD-810G compliant construction ensures durability against drops, shocks, and other environmental factors.
Camera Features Explained
Portrait Mode
Create professional-looking portraits with blurred background effects
HDR Mode
Capture better photos in high-contrast lighting conditions
Manual Mode
Full control over ISO, shutter speed, white balance, and focus
Gesture Shot
Take selfies using hand gestures without touching the phone
Time-lapse
Create accelerated videos of changing scenes over time
Beauty Mode
Enhance selfies with skin smoothing and facial feature adjustments
Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Phone won't turn on | Battery drained, power button issue | Charge for 30 minutes, then try powering on. Check power button |
| Poor battery life | Background apps, screen brightness, weak signal | Close unused apps, reduce brightness, enable battery saver |
| Slow performance | Low storage, too many apps running, need update | Clear cache, close background apps, check for software updates |
| Wi-Fi connection issues | Router problems, incorrect password, software glitch | Restart router, forget and reconnect network, restart phone |
| Camera not working | App crash, storage full, software issue | Clear camera app cache, free up storage, restart phone |
| Overheating | Heavy usage, direct sunlight, faulty battery | Close demanding apps, remove case, avoid direct sunlight |
Common Error Messages
- No SIM card detected: Reinsert SIM card, clean SIM contacts
- Insufficient storage: Delete unused apps/files, move to SD card
- App not responding: Force stop app, clear app cache and data
- Charging slowly: Use original charger, check charging port for debris
- Bluetooth connection failed: Restart Bluetooth, remove and re-pair device
- Touch screen unresponsive: Restart device, remove screen protector
Manual Downloads
LG K40 Series Manuals
LM-X420QM
LG K40 (US Version)
LM-X420EMW
LG K40 (European Version)
LM-X420N
LG K40 (Korean Version)
LM-X420Z
LG K40 (Asia Pacific Version)
Related Models
LM-X410QM
LG K30 (2019)
LM-X625QM
LG K50 (2019)
LM-X220QM
LG K20 (2019)
LM-X430QM
LG K40S (2020)