LG K30/K40 Problems, Known Issues & Troubleshooting lmx420 lmx410

In the lifecycle of an Android smartphone, we face many software and hardware issues.

The software problems are easier to fix. The software troubleshooting involves soft reset, hard reset, network settings reset, safe mode, software update, wiping the cache partition, deleting apps, moving apps to SD card, etc.

Hardware issues can be related to touchscreen digitizer, LCD, speaker, charging port, headphone jack, microphone, battery, camera, fingerprint scanner, flashlight, power button, sim card/sd card slot, etc.

Let’s check out the known K30/K40 issues and fix them with the help of the below troubleshooting guide  –

LG K30/K40 known issues/problems & fix

1. Charging Problems

lg k30 charging problems

The charging issues on K30/K40 can be in the form of slow charging, not charging, intermittent charging, battery question mark, etc.

The cause of charging problems can be software or hardware related. The software issues can be fixed with a reset. If your K30/K40 is not charging at all, the wall charger, charging port, or the battery needs to be checked.

Let’s go through all the possibilities in great detail and fix your K30/K40 charing issue –

LG K30/K40 Charging Problems – How to fix

2. Sound Problems

lg k30 sound problems

The sound problems on K30/K40 are quite common. The audio issues can be in the form of low volume, speaker not working, stuck in the headphone mode, microphone not working, can’t hear the caller, notification sounds not working, etc.

Let’s find the root cause of sound issues on your K30/K40 and fix them as per the below post –

LG K30/K40 Sound Problems – How to Fix

3. Running Slow / Lagging

lg k40 running slow

Is your K30/K40 lagging? The slow performance can be attributed to low storage space, background app or data activity, less available RAM, a downloaded app, etc.

Let’s once again make our phone blazing fast as per the below link –

LG K30/K40 Lagging Running Slow – How to make your K30/K40 faster


4. Frozen / keeps freezing

lg k30 frozen - k40 keeps freezing

Once in a while, our phone can freeze due to an app crash, low storage space, or if too many apps are open.

The immediate solution to this problem is a force restart. Press & hold the volume down & power button for 10 seconds or until the phone restarts.

If the freezing occurs occasionally, we need to find the root cause and fix this issue. Follow the troubleshooting steps in the below post to fix the freezing problem on your K30/K40 –

LG K40/K30 Frozen – Keeps freezing How to fix

5. Stuck on Secure Startup

lg k30 k40 secure startup bypass

The secure startup is just like a screen lock with an added security. If the secure startup is enabled, you won’t receive calls, texts & notifications until you unlock the screen. It’ll show up on every restart.

If you’ve forgotten the secure startup password, pattern, or pin, please follow the below tutorial to bypass this screen on LG K30 & K40 –


LG K30/K40 Secure Startup Bypass



6. Change Language / Language Settings

lg k40 language settings / k30 change language

Have you accidentally changed the system language on your K30/K40? A new language can be difficult to follow. We have to follow the path and icons to get access to the language settings page.

Let’s try to change the phone language to English. Follow the below post for a detailed explanation –

LG K30/K40 Language Settings


7. Block Number / Do Not Disturb

lg k30 k40 block number

An unwanted call can be quite annoying. Blocking and unblocking a number on K30/K40 is quite easy. We can even set a digit or word filter. We can also block calls and texts from unknown numbers/private numbers.

Let’s see how to block and unblock a number on K30/K40 as per the below article –

LG K30/K40 Block Number 

LG K30/K40 Do not disturb


8. Stuck on Firmware Update

lg k30 k40 firmware update stuck

My K30 was automatically taken to the Firmware Update screen when I connected it to my PC via a USB cable.  The bad USB cable was causing this issue.

Let’s see how to get out of the K30/K40 Firmware Update screen as per the below links –

LG K30 Firmware Update Stuck

LG K40 Stuck on Firmware Update

9. How to bypass Google verification

lg k30 k40 frp bypass 2021

Were you locked out on your K30/K40 and you reset the phone via recovery mode? The hard factory reset using the volume down & power button brings us to the Google verification page. It’s asking for the last-synced Google account.

If you don’t remember the Google credentials, follow the below guide to bypass the google FRP lock using the latest and easiest 2021 hack –

How to bypass google verification on LG K30

LG K40 FRP Bypass 2021 without a computer


10. Black Screen

lg k30 k40 black screen


When your K30/K40 screen is all black, it may be either on or off.  First of all, we need to make sure the phone is turning on or not. If it turns on but remains black, the LCD may have gone bad.

Let’s fix the black screen issue on K30 & K40 using the below troubleshooting steps –

LG K30/K40 Black Screen – how to fix 

11. Not turning on

lg k30 not turning on / k40 won't turn on

If your K30/K40 is all dead and not booting and all, the issue can be hardware related. We need to check the power button, charging port, battery & wall charger. Let’s try to bring our phone back to life as per the below guide –

LG K30/K40 Not turning on – how to fix 

12. LCD Screen Replacement

lg k40 lcd replacement

Most of the time, a phone LCD goes bad due to water or physical damage. You need to replace the whole LCD even if the touchscreen stops working. The digitizer only replacement is quite difficult.

If you wish the change the LCD on your own, you should better get a replacement LCD with a frame for precise fitting.


lg k30 screen replacement

Follow the below guide to replace your LG K30 LCD –

LG K30/K40 Screen Replacement Guide


13. Turn off mobile data/talkback/voice control/keyboard vibration/amber alerts

how to turn off mobile data lg k40

A few things/features on your K30/K40 can be annoying and you may like to turn it off for the time being.

Learn how to turn off mobile data, keyboard vibration, talkback, amber alerts, google assistant, voice control on your K30/K40 using the below post –

LG K40 turn off mobile data, keyboard vibration, talkback, etc.

14. How to get back the app drawer

lg k40 app drawer

By default, the home screen on K30/K40 is without an app drawer. We can easily get back the old style launcher with an app drawer icon –

LG K30/K40 App drawer – how to enable


15. Move apps to SD card/Storage space running out

lg k30 move apps to sd card

On K30/K40 hardly 16GB is usable space. It does have expandable memory, but we cannot install apps and games on an SD card.

The solution to this problem is Adoptable storage. Learn how to move apps to SD card and make it the default storage space for apps and games –

How to move apps to SD card on LG K30/K40



16. Boot Loop / Stuck on Logo Screen

lg k40 boot loop

If your K30/K40 is bricked, stuck in a boot loop, or stuck on the firmware update screen, we can restore it by flashing the stock firmware. Download the K30/K40 stock ROM and flash it using the LGUP flash tool as per the below guide –

LG K40 stock firmware download & update 

LG K30 stock ROM- firmware update

17. Wipe cache partition / Clear Cache

lg k30 k40 wipe cache partition

We don’t have the Black recovery mode screen with the “Wipe cache partition” option, anymore.  Learn how to wipe cache on K30/K40 using the below link –

LG K30/K40 Wipe cache partition


18. Delete Apps

how to delete apps on lg k30 k40

Make more space on your K30/K40 by deleting the unwanted apps and games. Learn how to delete apps on K30 & K40 as per the below post or video –

How to delete apps on LG K30 & K40



19. Forgot Password / PIN / Pattern

lg k40 forgot pin pattern password

If you’ve forgotten the lock screen PIN, Pattern, or password on your K30/K40, it won’t let you power off the phone until you unlock the screen.

The below troubleshooting guide explains how to bypass the LG K30/K40 lock screen using the latest hack –

LG K40 forgot password, pattern, pin

LG K30 lock screen bypass


20. Network lock / Service Provider Locked

lg k40 network lock

Except for the Factory unlocked variant, all the K30 & K40 models are locked for the respective carrier. You’ll see a network locked or service provider locked error if you insert a SIM card from another network.

To use your GSM phone worldwide, you need to unlock it first. Learn how to unlock LG K30 & K40 for free –

How to unlock LG K40 for free

How to unlock LG K30 for free





21. Screen mirroring without Chromecast

lg k40 screen mirroring without chromecast

LG K30/K40 doesn’t have the Cast, Smart view, or Screen sharing option anywhere on the phone. Still, we can mirror our K30/K40 screen to the TV with and without Chromecast. Let’s see how to do that –

LG K30 screen mirroring Roku, Firestick, etc. 

LG K40 Screen mirroring without Chromecast





22. Not showing missed calls / missed call notification

lg k40 missed call notification

A missed call notification is a very useful feature. It allows you to callback if you failed to attend the incoming call. Let’s see how to fix our K30/K40 if it’s not showing the missed calls by using the below troubleshooting guide –

LG K30/K40 missed call notification


Are you facing issues with your K30/K40? Were you able to fix it? Please share your experience in the comment section below.



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