LG LMK420YM Owner’s Manual
USER GUIDE
LM-K420YM
ENGLISH
Copyright ©2020 LG Electronics Inc. All rights reserved.
MFL71756201 (1.0)
www.lg.com
ENGLISH
About this user guide
Thank you for choosing this LG product. Please carefully read this user
guide before using the device for the first time to ensure safe and proper
use.
• Always use genuine LG accessories. The supplied items are designed
only for this device and may not be compatible with other devices.
• Descriptions are based on the device default settings.
• Default apps on the device are subject to updates, and support for
these apps may be withdrawn without prior notice. If you have any
questions about an app provided with the device, please contact an
LG Service Centre. For user-installed apps, please contact the relevant
service provider.
• Modifying the device’s operating system or installing software from
unofficial sources may damage the device and lead to data corruption
or data loss. Such actions will violate your LG licence agreement and
void your warranty.
• Some content and illustrations may differ from your device, depending
on the area, service provider, software version, or OS version, and are
subject to change without prior notice.
• Software, audio, wallpaper, images, and other media supplied with
your device are licenced for limited use. If you extract and use these
materials for commercial or other purposes, you may be infringing
copyright laws. As a user, you are fully responsible for the illegal use of
media.
• Additional charges may incur for data services, such as messaging,
uploading, downloading, auto-syncing and location services. To avoid
additional charges, select a data plan suitable to your needs. Contact
your service provider to obtain additional details.
1
Instructional notices
WARNING: Situations that could cause injury to the user and third
CAUTION: Situations that may cause minor injury or damage to the
NOTE: Notices or additional information.
parties.
device.
2About this user guide
Table of contents
6 Guidelines for safe and efficient use
01
Custom-designed
Features
14 Camera features
18 Audio recording features
18 Google Assistant
20 Fingerprint recognition
24 Multi-tasking feature
02
Basic Functions
28 Product components and
accessories
Parts overview
29
33 Turning the power on or off
34 Installing the SIM card
36 Inserting the memory card
37 Removing the memory card
37 Battery
40 Touch screen
43 Home screen
51 Screen lock
54 Memory card encryption
55 Taking screenshots
56 Content sharing
57 Do not disturb
3
03
04
Useful Apps
60 Installing and uninstalling apps
61 App Shortcuts
62 Phone
66 Messaging
67 Camera
77 Gallery
81 Contacts
84 QuickMemo+
86 Clock
87 Calculator
87 Music
88 ThinQ
89 Audio Recorder
89 Game Launcher
90 Smart Doctor
90 LG Mobile Switch
90 App trash
91 RemoteCall Service
91 Cell Broadcast
91 Google apps
Settings
95 Settings
95 Network & internet
101 Connected devices
103 Sound
105 Notifications
105 Display
106 Wallpaper & theme
106 Lock screen & security
108 Privacy
109 Location
109 Extensions
111 Apps
111 Battery
112 Storage
112 Accounts
112 Digital Wellbeing & parental
controls
Google
113
113 System
116 Accessibility
4Table of contents
05
Appendix
120 LG Language Settings
120 LG Bridge
121 Phone software update
123 Anti-Theft Guide
124 Open Source Software Notice
Information
Regulatory information
124
(Regulation ID number, E-labeling,
etc.)
125 Trademarks
126 Laser safety statement
126 DECLARATION OF
CONFORMITY
More information
127
129 FAQ
5Table of contents
Guidelines for safe and efficient use
Please read these simple guidelines. Not following these guidelines may be
dangerous or illegal.
Should a fault occur, a software tool is built into your device that will gather a
fault log. This tool gathers only data specific to the fault, such as signal strength,
cell ID position in sudden call drop and applications loaded. The log is used only to
help determine the cause of the fault. These logs are encrypted and can only be
accessed by an authorised LG Repair centre should you need to return your device
for repair.
Exposure to radio frequency energy
Radio wave exposure and Specific Absorption Rate (SAR) information.
This device has been designed to comply with applicable safety requirements for
exposure to radio waves. These requirements are based on scientific guidelines that
include safety margins designed to assure the safety of all persons, regardless of
age and health.
• The radio wave exposure guidelines employ a unit of measurement known
as the Specific Absorption Rate, or SAR. Tests for SAR are conducted using
standardised methods with the device transmitting at its highest certified
power level in all used frequency bands.
• While there may be differences between the SAR levels of various LG device
models, they are all designed to meet the relevant guidelines for exposure to
radio waves.
• The SAR limit recommended by the International Commission on Non-Ionizing
RadiationProtection(ICNIRP)is2W/kgaveragedover10goftissue.
• The highest SAR value for this model tested for use at the ear is 0.606 W/kg
(10g)andwhenwornonthebodyis1.504W/kg(10g).
• This device meets RF exposure guidelines when used either in the normal use
positionagainsttheearorwhenpositionedatleast5mmawayfromthebody.
When a carry case, belt clip or holder is used for body-worn operation, it should
notcontainmetalandshouldpositiontheproductatleast5mmawayfrom
your body. In order to transmit data files or messages, this device requires a
quality connection to the network. In some cases, transmission of data files
or messages may be delayed until such a connection is available. Ensure the
above separation distance instructions are followed until the transmission is
completed.
6
Product care and maintenance
• Use only in-box accessories which are authorised by LG. LG does not guarantee
any damage or failure which is caused by third party accessories.
• Some contents and illustrations may differ from your device without prior
notice.
• Do not disassemble this unit. Take it to a qualified service technician when repair
work is required.
• Repairs under warranty, at LG’s discretion, may include replacement parts
or boards that are either new or reconditioned, provided that they have
functionality equal to that of the parts being replaced.
• Keep away from electrical appliances such as TVs, radios and personal
computers.
• The unit should be kept away from heat sources such as radiators or cookers.
• Do not drop.
• Do not subject this unit to mechanical vibration or shock.
• Switch off the device in any area where you are required to by special
regulations. For example, do not use your device in hospitals as it may affect
sensitive medical equipment.
• Do not handle the device with wet hands while it is being charged. It may cause
an electric shock and can seriously damage your device.
• Do not charge a handset near flammable material as the handset can become
hot and create a fire hazard.
• Use a dry cloth to clean the exterior of the unit (do not use solvents such as
benzene, thinner or alcohol).
• Do not charge the device when it is on soft furnishings.
• The device should be charged in a well ventilated area.
• Do not subject this unit to excessive smoke or dust.
• Do not keep the device next to credit cards or transport tickets; it can affect the
information on the magnetic strips.
• Do not tap the screen with a sharp object as it may damage the device.
• Do not expose the device to liquid or moisture.
• Use accessories like earphones cautiously. Do not touch the antenna
unnecessarily.
7Guidelines for safe and efficient use
• Do not use, touch or attempt to remove or fix broken, chipped or cracked glass.
Damage to the glass display due to abuse or misuse is not covered under the
warranty.
• Your device is an electronic device that generates heat during normal operation.
Extremely prolonged, direct skin contact in the absence of adequate ventilation
may result in discomfort or minor burns. Therefore, use care when handling your
device during or immediately after operation.
• If your device gets wet, immediately unplug it to dry off completely. Do not
attempt to accelerate the drying process with an external heating source, such
as an oven, microwave or hair dryer.
• The liquid in your wet device, changes the colour of the product label inside your
device. Damage to your device as a result of exposure to liquid is not covered
under your warranty.
• A mobile device requires proper air circulation in order to dissipate heat. Direct
skin contact and inadequate circulation of air flow to the device may cause the
device to overheat. The device must be at least 1.0cm from between the user’s
body.
• Prevent dust of any other foreign substances from getting into the Charger/
USB cable port. It may cause heat or fire.
• Avoid exposing the device to low air pressure at high altitude.
• Do not expose the device to extremely low air pressure. Otherwise, it can cause
explosion of the battery or leakage of flammable liquid or gas.
• Please ensure that the product does not get in contact with liquid. Do not use
or recharge the product if it is wet. Once the product becomes wet, the liquid
damage indicator changes colour. Please note that this will limit you from
receiving any free-of-charge repair services provided under warranty.
8Guidelines for safe and efficient use
Efficient device operation
Electronics devices
All devices may receive interference, which could affect performance.
• Do not use your device near medical equipment without requesting permission.
Please consult your doctor to determine if operation of your device may
interfere with the operation of your medical device.
•
Pacemakermanufacturersrecommendthatyouleaveatleast15cmofspace
between other devices and a pacemaker to avoid potential interference with the
pacemaker.
• This device may produce a bright or flashing light.
• Some hearing aids might be disturbed by devices.
• Minor interference may affect TVs, radios, PCs etc.
Useyourdeviceintemperaturesbetween0ºCand40ºC,ifpossible.Exposing
•
your device to extremely low or high temperatures may result in damage,
malfunction, or even explosion.
Road safety
Check the laws and regulations on the use of devices in the area when you drive.
• Do not use a hand-held device while driving.
• Give full attention to driving.
• Pull off the road and park before making or answering a call if driving conditions
so require.
• RF energy may affect some electronic systems in your vehicle such as car
stereos and safety equipment.
• When your vehicle is equipped with an air bag, do not obstruct with installed
or portable wireless equipment. It can cause the air bag to fail or cause serious
injury due to improper performance.
• If you are listening to music whilst out and about, please ensure that the volume
is at a reasonable level so that you are aware of your surroundings. This is of
particular importance when near roads.
9Guidelines for safe and efficient use
Avoid damage to your hearing
To prevent possible hearing damage, do not listen at high volume
levels for long periods.
Damage to your hearing can occur if you are exposed to loud sound for long
periods of time. We therefore recommend that you do not turn on or off the
handset close to your ear. We also recommend that music and call volumes are set
to a reasonable level.
• When using headphones, turn the volume down if you cannot hear the people
speaking near you, or if the person sitting next to you can hear what you are
listening to.
• Excessive sound pressure from earphones and headphones can cause
hearing loss.
Glass Parts
Some parts of your device are made of glass. This glass could break if your device is
dropped on a hard surface or receives a substantial impact. If the glass breaks, do
not touch or attempt to remove it. Stop using your device until the glass is replaced
by an authorised service provider.
Blasting area
Do not use the device where blasting is in progress. Observe restrictions and follow
any regulations or rules.
Potentially explosive atmospheres
• Do not use your device at a refueling point.
• Do not use near fuel or chemicals.
• Do not transport or store flammable gas, liquid or explosives in the same
compartment of your vehicle as your device or accessories.
In aircraft
Wireless devices can cause interference in aircraft.
• Turn your device off before boarding any aircraft.
• Do not use it on the ground without permission from the crew.
10Guidelines for safe and efficient use
Children
Keep the device in a safe place out of the reach of small children. It includes small
parts which may cause a choking hazard if detached.
Emergency calls
Emergency calls may not be available on all mobile networks. Therefore you should
never depend solely on your device for emergency calls. Check with your local
service provider.
Battery information and care
• You do not need to completely discharge the battery before recharging. Unlike
other battery systems, there is no memory effect that could compromise the
battery’s performance.
• Use only LG batteries and chargers. LG chargers are designed to maximise the
battery life.
• Do not disassemble or short-circuit the battery.
• Keep the metal contacts of the battery clean.
• Replace the battery when it no longer provides acceptable performance. The
battery pack may be recharged hundreds of times before it needs replacing.
• Recharge the battery if it has not been used for a long time to maximise
usability.
• Do not expose the battery charger to direct sunlight or use it in high humidity,
such as in the bathroom.
• Do not leave the battery in hot or cold places, as this may deteriorate battery
performance.
• Risk of explosion if battery is replaced by an incorrect type. Dispose of used
batteries according to the instructions.
• If you need to replace the battery, take it to the nearest authorised LG
Electronics service point or dealer for assistance.
• Always unplug the charger from the wall socket after the device is fully charged
to save unnecessary power consumption of the charger.
• Actual battery life will depend on network configuration, product settings,
usage patterns, battery and environmental conditions.
• Make sure that no sharp-edged items such as animal’s teeth or claws, come
into contact with the battery. This could cause a fire.
11Guidelines for safe and efficient use
Securing personal information
• Make sure to protect your personal information to prevent data leakage or
misuse of sensitive information.
• Always back up important data while using the device. LG is not responsible for
any data loss.
• Make sure to back up all data and reset the device when disposing of the device
to prevent any misuse of sensitive information.
• Read the permission screen carefully while downloading applications.
• Be cautious using the applications that have access to multiple functions or to
your personal information.
• Check your personal accounts regularly. If you find any sign of misuse of your
personal information, ask your service provider to delete or change your account
information.
• If your device is lost or stolen, change the password of your account to secure
your personal information.
• Do not use applications from unknown sources.
Notice for Battery replacement
• For your safety, do not remove the battery incorporated in the product.
If you need to replace the battery, take it to the nearest authorised LG
Electronics service point or dealer for assistance.
• Li-Ion Battery is a hazardous component which can cause injury.
• Battery replacement by a non-qualified professional can cause damage
to your device.
12Guidelines for safe and efficient use
01
Custom-designed Features
Camera features
x1.0
Change the
Wide-angle camera
You can take photos or record videos with a wider range than your actual
field of vision by using the wide-angle on the rear camera.
, then tap
Tap
angle.
• See
Gallery overview
• You can switch between the standard and wide-angle camera lenses on
the rear camera only.
/ to switch between the standard and wide-
camera angle.
Rear Camera
for details.
Custom-designed Features 14
Portrait
You can take a sharp portrait by applying the camera lens blur effect.
Tap , then tap Portrait.
1
Tap to take a photo.
2
• Keep the distance to your subject within 1.3 ~ 5.0 feet when using the
rear camera.
• This feature is not available if the surroundings are too dark.
• After applying this feature, tap the desired position on the preview
screen to automatically apply the exposure value and focus when using
the rear camera, or exposure value only when using the front camera.
Custom-designed Features 15
AI CAM
You can effectively take photos or record videos since the camera
recognises the object when taking a photo or recording a video.
Tap , then tap AI CAM.
1
When the object is recognised, the best effect for the scene is applied.
2
• To apply other effects, tap the scene icon.
• Pet, city, flower, food, landscape, person, sunset, auto, total 8
categories can be recognised automatically.
Sunset Flower
• The result of the scene recognition may differ depending on the
illumination or the location of the subject while taking photos. Keywords
do not appear on the actual photos or videos.
• This feature is available only when the front and rear cameras are in the
AI mode.
Custom-designed Features 16
Sticker
You can apply a variety of stickers to your photos or videos.
You can create richer content by using 3D AR Effect.
Tap and select Sticker by swiping camera modes.
1
• Select a desired sticker by swiping stickers.
Tap to take a photo, or tap and hold to record a video.
2
• The front and rear cameras cannot be switched while recording a
video.
Tap to end the video recording.
3
• The photo or video will be saved in Gallery.
Set timer settingSet camera
Choose screen ratio
Custom-designed Features 17
Audio recording features
LG 3D Sound Engine
LG 3D Sound Engine feature allows you to hear stereoscopic and
optimised sound. When playing music or video, you can enjoy stereoscopic
and immersive sound as if you were listening in the field.
Drag the notifications panel downwards.
1
Tap Settings Sound Sound quality and effects LG 3D Sound
2
Engine and tap
• If you connect an external audio device such as an earphone or speaker
to the product, a pop-up appears to turn on the LG 3D Sound Engine
feature.
to activate it.
Google Assistant
Google Assistant overview
Your device has the built-in Google Assistant feature. Find answers and
get things done while on-the-go.
• To use this feature, first connect to the network.
Launching Google Assistant
Press the Google Assistant key on the left side of the device.
1
or
Swipe diagonally from a bottom edge corner of the screen.
Tap GET STARTED.
2
Follow the on-screen instructions.
3
Custom-designed Features 18
• The device saves your voice data for recognition.
Set whether to use the voice match unlock function.
4
• If you use the voice match unlock function, you can unlock the
device even when the device screen is turned off or the device is
charging by saying “OK Google” or “Hey Google”.
• This feature may be more vulnerable to security than the other screen
locks, such as Pattern, PIN, and Password.
When a similar voice or your recorded voice is used, the screen may be
unlocked.
• To use this feature, on the home screen, tap Settings
& security
screen lock method you set to unlock the device.
• You need to unlock the device by using the specified method if you fail to
unlock the device with voice recognition. See
Tap Finish.
5
Secure lock settings Smart Lock, and then use the
Setting a screen lock
Lock screen
Accessing by Voice
When the home screen is turned off or locked, say “OK Google” or
1
“Hey Google”.
When the Google Assistant screen appears, say a command or ask a
2
question.
Accessing from Home Screen
Press the Google Assistant key on the left side of the device.
1
or
Swipe diagonally from a bottom edge corner of the screen.
Say a command or question when you see on the bottom of the
2
screen.
for details.
Custom-designed Features 19
• In an environment where Wi-Fi or mobile data connection is poor, the
Google Assistant function may be restricted and the speech recognition
accuracy rate may be lowered.
• If the speech is ambiguous, the microphone is covered, a media player is
playing, or the surrounding is loud, the speech recognition accuracy rate
may be lowered. When you are using the product via voice commands,
say with accurate pronunciation in a quite environment for better
speech recognition accuracy.
Fingerprint recognition
Fingerprint recognition overview
You must register your fingerprint on your device first before using the
fingerprint recognition function.
You can use the fingerprint recognition function in the following cases:
• To unlock the screen.
• To view the locked content in the QuickMemo+.
• Confirm a purchase by signing into an app or identifying yourself with
your fingerprint.
• You can use fingerprint data for user authentication. There is a
possibility that the fingerprint sensor might recognise a different but
very similar fingerprint as the same registered fingerprint. To strengthen
security, it is recommended that you use the pattern, PIN, or password
method for unlocking the screen.
• If the device cannot detect your fingerprint or you forgot the value
specified for registration, visit the nearest LG Customer Service Centre
with your device and ID card.
Custom-designed Features 20
Precautions for fingerprint recognition
Fingerprint recognition accuracy may decrease due to a number of
reasons. To maximise the recognition accuracy, check the following before
using the device.
• At the bottom centre of the product’s screen, there is a built-in sensor
that recognises fingerprints. Be careful not to scratch or damage the
fingerprint sensor with metal objects such as coins or keys.
• If there are foreign substances (sweat, lotion, water, dirt, grease, etc.)
on the fingerprint sensor or on the finger to be put on the sensor,
fingerprint recognition may not work properly. Wipe the sensor and the
finger clean and remove all moisture before putting the finger on the
sensor.
• If the finger’s surface is rough due to it being scarred or pruney from
water, the sensor may not be able to recognise the fingerprint. In such
a case, register another fingerprint.
• If you bend your finger or use the fingertip only, your fingerprint may
not be recognised. Make sure that your finger covers the entire surface
of the fingerprint sensor.
• Scan only one finger for each registration. Scanning more than one
finger may affect fingerprint registration and recognition.
• The device may generate static electricity if the surrounding air is dry.
If the surrounding air is dry, avoid scanning fingerprints, or touch a
metallic object such as a coin or a key before scanning fingerprints to
remove static electricity.
Custom-designed Features 21
Registering fingerprints
You can register and save your fingerprint on the device to use fingerprint
identification.
On the home screen, tap Settings Lock screen & security
1
Fingerprints.
• A lock screen must be set in order to be able to use this feature.
• If the screen lock is not active, configure the lock screen by following the
on-screen instructions. See
Place your finger on the fingerprint sensor on the device and adjust it
2
little by little.
• Gently press the fingerprint sensor so that the sensor can recognise
your fingerprint.
• Ensure that your finger covers the entire surface of the fingerprint
sensor.
Setting a screen lock
for details.
Follow the on-screen instructions.
3
• Until the fingerprint registration is completed, move the same finger
around on the sensor little by little.
• Put the finger on the sensor. When you feel a vibration, remove the
finger from the sensor.
Custom-designed Features 22
When the fingerprint registration is done, tap OK.
4
• Tap Add more to register another fingerprint. Since the fingerprint
recognition success rate depends on the condition of the registered
fingerprint, it is recommended that you register several different
fingerprints.
Managing fingerprints
You can edit or delete registered fingerprints.
On the home screen, tap Settings Lock screen & security
1
Fingerprints.
Unlock according to the specified lock method.
2
From the fingerprint list, tap a fingerprint to rename it. To delete it, tap
3
.
Unlocking the screen with a fingerprint
You can unlock the screen or view the locked content by using your
fingerprint. Activate the desired function:
On the home screen, tap Settings Lock screen & security
1
Fingerprints.
Unlock according to the specified lock method.
2
On the fingerprint settings screen, activate the desired function:
3
• Screen lock: Unlock screen with a fingerprint.
• Content lock: Unlock content with a fingerprint. To do this, make
sure that the content lock is set.
• Screen unlock when screen is off: Unlock screen even when the
screen is off by placing your finger on the Power key.
Custom-designed Features 23
Multi-tasking feature
Recent Uses Screen
Swipe the Home button upward and hold to view the recent use
history.
Pop-up window
You can open multiple apps on the screen and easily switch between
them at any time.
Swipe up on from the bottom of the screen.
1
Tap the app icon on the top left of the app screen and select Pop-up
2
window.
• If you tap the app icon, the App info, Multi window, Pop-up
window and Pin app options appear.
The app appears in the form of a pop-up window on the screen.
3
• This feature may not be available in some apps or screens.
Custom-designed Features 24
Using the pop-up window
• : Minimises the pop-up window. The pop-up window is minimised
into the app icon floating on the screen, which can be moved anywhere
you want.
: Expands the app to full screen.
•
: Closes the app.
•
• You can open up to 5 apps using the pop-up windows.
• To select an app from the opened apps, tap one of the pop-up windows.
The selected pop-up window comes to the front.
• Pop-up windows cannot be moved to the status bar or navigation bar
area.
Using the app folder for pop-up windows
If you tap on the pop-up window, the pop-up window is minimised into
the app icon.
You can move the app icon anywhere you want by dragging it.
If two or more pop-up windows are minimised, the app folder is created to
contain the app icons.
• The recently-used app icon is used as the app folder icon. If you tab the
icon, all the icons for the minimised pop-up windows appear in the app
folder.
• If you touch and hold the app folder for pop-up windows and drag the
app folder into Remove, the app folder will be removed.
• To remove one of the apps from the app folder, open the app folder and
drag the app icon out of the app folder.
Custom-designed Features 25
Multi window
When using gesture navigation
Swipe up on from the bottom of the screen.
1
• Recently-used apps appear.
• If you tap the app icon, the App info, Multi window, Pop-up
window and Pin app options appear.
Tap the app icon on the top left of the app to be displayed in the
2
multiwindow and select Multi window.
• The selected app appears at the top half of the screen.
Tap the other app to be displayed in the multi window.
3
• The selected app appears at the bottom half of the screen.
When using Buttons only navigation
Tap on the navigation bar.
1
• Recently-used apps appear.
• If you tap the app icon, the App info, Multi window, Pop-up
window and Pin app options appear.
Tap the app icon on the top left of the app to be displayed in the
2
multiwindow and select
• The selected app appears at the top half of the screen.
Tap the other app to be displayed in the multi window.
3
• To adjust the size of the split screen, drag the bar on the centre of the
screen.
• To deactivate the multi window feature, drag the centre bar up or down
to the end of the screen.
• The multi window feature is not supported in some LG apps or apps
downloaded from the Play Store.
.
Custom-designed Features 26
02
Basic Functions
Product components and accessories
The following items are included with your device.
• Device
• USB cable
• Ejection pin
• The items described above may be optional.
• The items supplied with the device and any available accessories may
vary depending on the area and service provider.
• Always use genuine LG Electronics accessories. Using accessories made
by other manufacturers may affect your device's call performance or
cause malfunctions. This may not be covered by LG's repair service.
• Some of the device parts are made of tempered glass. If you drop your
device on a hard surface or subject it to severe impact, the tempered
glass may be damaged. If this happens, stop using your device
immediately and contact an LG Customer Service Centre.
• If any of these basic items are missing, contact the dealer from which
you purchased your device.
• To purchase additional items, contact an LG Customer Service Centre.
• Some items in the product box are subject to change without notice.
• The appearance and specifications of your device are subject to change
without prior notice for product improvement.
• Device specifications may vary depending on the area or service provider.
• Remove the protective film from the Fingerprint sensor before using the
fingerprint recognition feature.
• Charger
• Quick Start Guide
Basic Functions 28
Parts overview
Earpiece
Front camera lens
Volume keys (+/-)
Google Assistant key
Stereo headset jack
Proximity/Ambient light
sensor
Power/Lock key
/Fingerprint sensor
Touch screen
Charger/USB cable port
Microphone
Rear camera lenses
Basic Functions 29
Flash
Speaker
Nano-SIM/
Memory card tray
NFC
Microphone
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