HOW TO FLASH/UNBRICK OR UPGRADE LG ANDROID DEVICES

Experimenting on your LG android smart phone with custom roms, apps, root etc is always enjoyable. But sometimes things can go wrong and the device will no longer be able to boot up. In this situation, the only way for you is to flash the Stock ROM/Firmware of the device. This can be done using LG Flash Tool. 
This process can also be used if you want to upgrade or downgrade your device to any official android version of the device released by LG.

Download the stock rom (firmware) of the LG device you want to flash/unbrick or update/downgrade. They are normally in kdz format.
Download and install LG drivers from here.
Download and extract LG Flash Tool from here.
Copy KDZ file from ROM (firmware) folder into LG Flash Tool Folder.
Make sure at least 25% of battery life is available on the device.
Boot the device into download mode by holding volume down button or volume up button then connect device to PC with usb.

Launch LGFlashTool2014 as administrator (If it cannot start, download and install visual c++ runtime).

• Select Type - CDMA
• Phone Mode - DIAG
• Select KDZ File (Choose the KDZ file inside the LG FLash Tool folder)

Click Normal for flashing the device without loosing any data.

Click CSE Flash to do a full flash of the device. Use this when upgrading, downgrading or unbricking the device.

Click START.

A dialogue box will appear for you to select language. Click OK.

Now Wait for the process to reach 100%

First boot after flash will take a while......