Tips and tricks to fix X4 (2019) or LG K40 or LG K12 PLUS problems. This phone have several name depend on region release. but both version have same specifications. This phone have 5.7 inches LCD screen with Android Oreo version 8.1 as factory default operating system together with LG user interface which known as LG UX 7. This phone release for budget or low end smartphone with standard internal memory capacity 32 GB and 2 GB or 3 GB RAM. LG K12 PLUS / K40 / X4 (2019) use Mediatek MT6762 Helio P22 64 bit processor with 12 nm processor technology. Find more review and information about how to solve troubles of LG K12 PLUS / K40 / X4 (2019) at community.


What is Advantage of LG K12 PLUS / K40 / X4 (2019) Specifications?

Network GSM 3G HSDPA or with 4G LTE
LCD 5.7 inches
Processor Octa-core 2.0 GHz Cortex-A53
GPU PowerVR GE8320
Bluetooth / GPS / Wifi
Memory Internal 32 GB
RAM 2 GB or 3 GB
External memory 1000 GB microSD
Main Camera 16 MP, f/2.0, autofocus & LED flash
Front Camera 8 MP for video conference and selfie photography
Operating System Android Oreo version 8.1
Battery Li-Ion 3000 mAh



How to Fix or Problem Solving for Recovery LG K12 PLUS / K40 / X4 (2019) hang or not responding or malfunctions or stuck or freezing or bricked ?

Although this phone is entry level smartphone with cheap price, but some standard users still can use this phone without problems, especially when we use 3 GB RAM. However, if we use cheaper 2 GB RAM smartphone, we suggest to not install many chatting applications, because it will stay to use RAM for multitasking applications. Having LG K12 PLUS / K40 / X4 (2019) already have 32 GB internal storage, this is important to install more applications from Google Play Store like social media Facebook or chatting applications Whatsapp or Kakaotalk or WeChat and some other important apps.

There are some applications inside Google Play Store which may contain bad stuff like viruses or malware that can make some troubles at our LG K12 PLUS / K40 / X4 (2019) if we install such as hang or stuck or frozen or bricks or LCD touch screen not responsive. These bad apps will not get any Verified by Play Protect information at downloaded process. Please note, usually Editor choice is good options to try for safety reasons.

What do we have to do when we get this trouble? First we have to remove temporary files and caches inside this phone by doing soft reset. After our LG K12 PLUS / K40 / X4 (2019) can run again, then please try to download one good antivirus like NORTON or AVAST. It will scan all installed applications and give recommendation if there are some high-risk setting. If the problems still happen, then next steps is doing hard reset or master format. Please note, doing hard reset will remove or erase all important data, therefore we have to backup all data first before doing master format. Doing hard reset will remove all Google account from LG K12 PLUS / K40 / X4 (2019). For safety reasons, please do not install any unknown APK files, because it is very easy to make our phone getting trouble.


How to Force Shutdown or Force Soft Reset or Reboot or Restart LG K12 PLUS / K40 / X4 (2019) ?

This phone have limited specifications, sometime installed apps get crash or corrupt and make LG K12 PLUS / K40 / X4 (2019) will run not normal such as hang or LCD touch screen not responding with finger touch. We need to force remove temporary files and caches inside this phone. Please press and hold POWER button until LG K12 PLUS / K40 / X4 (2019) shutdown or turn off by itself. If it is not work, then try to press and hold POWER + VOLUME DOWN together until shutdown. After it totally off, then we can press again POWER button to turn it ON. This process will not remove any important data, therefore we can do this process anytime we want. If our LG K12 PLUS / K40 / X4 (2019) still can work properly, but we want to clear temporary files and caches from some applications, then please press and hold POWER button until pop-up menu appear, continue choose Shutdown / Power off / Reboot menu.



How to backup data or Contact at LG K12 PLUS / K40 / X4 (2019) ?

We can use microSD external card to copy or move important files using File Manager applications. If our LG K12 PLUS / K40 / X4 (2019) has already signed in with Google account, by default our contact will be synchronize in the background to Google server. Please make sure we check all contact at Google contact server using Internet browse to make sure backup is done.


#Option 1, Hard Reset LG K12 PLUS / K40 / X4 (2019) with software menu

  1. Turn on the LG K12 PLUS / K40 / X4 (2019)
  2. Make sure the battery is not empty
  3. Backup important data at LG K12 PLUS / K40 / X4 (2019) because all data and applications will be erase or delete
  4. Go to Menu :  Setting > Backup and Reset > Factory Data Reset
  5. Choose : Reset Device > Delete all
  6. The LG K12 PLUS / K40 / X4 (2019) will do the master reset process.


hard reset lg k12 plus / k40 / x4 2019

#Option 2, Hard Reset LG K12 PLUS / K40 / X4 (2019) Factory Default using Hardware Secret Button Key

In some conditions, we can not do anything at LG K12 PLUS / K40 / X4 (2019) touch screen or frozen in some state. So we can not access reset menu like Option #1, do not worry, because we can do hard reset LG K12 PLUS / K40 / X4 (2019) with hardware key button:

  1. Turn off the LG K12 PLUS / K40 / X4 (2019)
  2. Make sure the battery LG K12 PLUS / K40 / X4 (2019) already full or more than 50%
  3. Press together and hold the Power Button + Volume Down Button
  4. If the Logo appear, then release the Power Button (do not release the Volume Down Button), then continue to press again the Power Button until Recovery mode / Factory reset menu appear, then we can release all button now.
  5. Choose wipe data/factory reset using Volume Button, and press Power Button to Enter or OK
  6. The LG K12 PLUS / K40 / X4 (2019) will continue master reset, wait for several minutes until the phone start like new again.


How to Unlock or Fix or Bypass or Solutions for LG K12 PLUS / K40 / X4 (2019) forgot password code or security lock screen pattern or pin (lost password)?


As cheap smartphone, this phone still have fingerprint sensor like mid end smartphone. It is located at back side of body. We need to register our fingerprint several time to make it recognize for unlock. For safety reasons, this phone will ask for secondary protections to backup for unlock when fingerprint can not work. We can choose secondary protections such as screen lock pattern or password pin protections. The problems will be happen when we forgot security answer or fingerprint can not unlock our phone, what should we do?

Do not worry because we can unlock or bypass forgotten screen lock pattern or password pin protections at LG K12 PLUS / K40 / X4 (2019) use registered Google account. Please note that Google account is very important. This phone already use latest version of Android operating system, therefore LG K12 PLUS / K40 / X4 (2019) implement FRP (factory reset protection) to make our phone safe from hard reset when stolen or lost. After finish hard reset or master format with hardware button combination key, this phone will Verify your account with previous Google Account that has been used before performing hard reset.


Is That Any Secret Code for Doing Format LG K12 PLUS / K40 / X4 (2019)?

There is no secret hidden code for LG K12 PLUS / K40 / X4 (2019) to make it back to factory default. Do the options above to hard reset it.


How to Format or Erase Phone Memory at LG K12 PLUS / K40 / X4 (2019) ?

There are two phone memory type at LG K12 PLUS / K40 / X4 (2019) , one is internal memory and the other one is external memory. If we want to format internal memory phone then we have to do hard reset or reformat the operating system of LG K12 PLUS / K40 / X4 (2019) as well. Please use menu setting to do hard reset or reformat using #option 1 above, but make sure to give checkbox mark at Erase Internal SD card / Internal storage. Then it will reformat the factory default operating system and remove or erase any data inside internal memory.

To reformat or wipe or erase all data at external memory, we can use menu Setting > Storage > Erase Internal Storage / SD Card. Please always make sure all data has already backup before reformat or wipe everything, because it is hard to recover formatted / wiped data at internal or external storage.


How to Make Battery of LG K12 PLUS / K40 / X4 (2019) Stronger, Life Longer and Not Fast to Drain ?

LG K12 PLUS / K40 / X4 (2019) use 3000 mAh battery. This capacity actually is enough for 5.7 inches LCD screen smartphone with 12 nm processor technology. Many users can use this phone full one day without need to recharge. But if we use this phone for playing games or watch movie several hours continuously, then our LG K12 PLUS / K40 / X4 (2019) battery will not enough. We have to do some adjustment like make LCD screen brightness as low as possible. Disable all not use connections to make battery work longer like GPS or NFC or Bluetooth or Wifi. If some applications need to know our location, then please choose GPS battery Saving Mode from menu Setting > Location.