OTA System Updates have made our life easier. A few years ago the updates were done using the computer via PC suite.
To upgrade our LG K40 firmware, we’ve to download & install the firmware file via the Update Center in Settings.
If you mess with your K40 while the update is installing, it will stick to the Firmware Update screen (Download Mode). A corrupt firmware file can also lead to this behavior. A failed system update can get you stuck to the firmware update screen.
A bad USB Cable can also bring your K40 to the Firmware Update Screen/Download Mode. This happened to me once.
In this post, we are going to learn how to restore a bricked LG K40 when stuck on the Firmware Update screen. You can also use this tutorial to unbrick your phone if it’s stuck in a boot loop (keeps restarting).
So, Let’s proceed with the troubleshooting –
LG K40 Stuck on Firmware Update / Boot Loop / Bricked
Troubleshooting Step 1
My K40 was off. I connected it to a charger and It got stuck to the above Firmware Update Screen.
Later on, I realized the USB Cable is bad. Because the same thing happened when I charged my K30 using the same USB Cable.
How to get LG K40 out of Firmware Update Screen
To force restart your K40 –
Press the Volume Down & Power Button for 10 seconds or until the phone reboots.
This method works most of the time. However, if your K40 is soft bricked, we can restore it only by flashing the stock firmware as follows –
Troubleshooting Step 2
A failed LG K40 system update will take you to the above “Firmware Update” Screen. This is also known as the Download Mode.
In case your K40 is stuck in a boot loop, you need to boot the phone into download mode to flash the stock firmware. Learn how to boot your K40 into Download Mode using the below link –
We use the LG K40 Download Mode to flash a kdz system firmware via LGUP Flash Tool.
First of all, download the necessary files as follows –
1. LG K40 Driver.exe
2. LGUP Dual Mode.zip – Download the zip file and extract in on your computer
3. LG K40 Stock Firmware.zip – Download the zip file and extract in on your computer to get the kdz file
You can see I’ve downloaded the above files.
First of all, Let’s install the LG Mobile Driver.
Double-Click the driver setup file as shown above.
Follow the on-screen prompts to complete the driver installation.
Now, we are ready to connect our K40 to the computer via a Micro USB data cable.
We have to wait for the installation of the USB Serial Port & USB Modem Driver. You can check the installation status via Device Manager on your PC.
In the next step, we have to extract the LGUP_DualMode.zip file. Open the extracted folder as shown above.
Install the LGUP Store v1.14 file. Double-click the setup file to install it.
Finish the installation but don’t run the LGUP tool as of now.
Right-Click the “SetUser” file and select “Run as administrator” as shown in the above screenshot.
Now, double-click the LGUPU file to load the LGUP Flash tool.
The LGUP window is open. It shows the connected phone model (LM-X420MM) & the current firmware version (X420MM10d).
Tap below “File Path” to highlight it.
Now, hit the “3 dots icon” as shown above. We have to browse and select the downloaded LG K40 stock firmware file.
The extracted K40 kdz file is “X420MM10g_00_MPCS_US_OP_08-8.kdz”. Select this file and Open it in LGUP.
The kdz file is loaded. We are now ready to flash this file on our K40.
Before hitting “START”, Change the process to “UPGRADE” as shown above. By default it’s set to “REFURBISH”.
Keep checking the Progress on the phone screen as well as in LGUP.
Don’t disturb the connection between the phone and the PC until the process is complete.
LGUP shows 80% progress and the K40 is rebooting.
Now the Progress bar says 100% complete.
We have successfully restored our LG K40 back to the normal working state.
If facing any issue, feel free to leave a comment below.
try this first, press power + volume up and down. it will reboot. and should work again