Below you can find the direct download URL for United States LG-K428SG Stock KDZ firmware from LG server.
IMEI:357795071xxxxxx
Model: LG-K428SG
Suffix: ATMFOP
Buyer: TMF
Country: United States
Carrier: TMUS_FRU
Software Version: K42820L_00
OS Version: N
File Name: K42820l_00_0620.kdz
Download:http://pkg02.lime.gdms.lge.com/dn/downloader.dev?fileKey=FWE7GOW0A2HIACPB251EJCF/K42820l_00_0620.kdz
Can not download the kdz file from above URL with a browser? PLEASE download and install XDM download manager first . Just copy above URL and start a new Download JOB in XDM download manager to save the K42820l_00_0620.kdz onto your computer.
KK = Android Kitkat LMR1 or L = Android llolip MMR1 or M = Android Marshmallow NMR1 or N = Android Nougat OMR1 or O = Android Oreo
Learn how to flash K42820l_00_0620.kdz with LGUP, Check this Guide.
A hard reset or master reset can fix almost all software and apps issues on LG-K428SG smartphone. Learn how to perform a reset, please have a look at LG-K428SG owners manual.
Bypass Google FRP on LG-K428SG? flashing the stock kdz firmware for LG-K428SG does not allow you to bypass the Google Account Verification process.
LG-K428SG SIM-unlock? flashing stock firmware with LGUP can not unlock your LG-K428SG phone.
Below you can download some useful tools and Software:
Download: LGUP 1.14 https://drive.google.com/open?id=1SOhoR2hn9PKiIvUUeiDVeX-8PfuMx1qq
LG Bridge windows: LGBridge_Setup.exe
LG Bridge Mac:LGBridge_Mac.dmg
/LGMobileDriver_WHQL_Ver_4.2.0.exe [Latest LG USB drivers 4.2] for Windows