Model: LGD620R
Buyer: P4P
Suffix: P4P
Area: Europe
Carrier: P4
Country: Poland
Version: D620r20b_00
Download: D620r20b_00.kdz
KDZ URL: http://pkg02.cdn.gdms.lge.com/dn/downloader.dev?fileKey=FW8FBL6232YUA8M7AB33BK3/D620r20b_00.kdz
Model: LGD620R
Buyer: P4P
Suffix: P4P
Area: Europe
Carrier: P4
Country: Poland
Version: D620r20b_00
Download: D620r20b_00.kdz
KDZ URL: http://pkg02.cdn.gdms.lge.com/dn/downloader.dev?fileKey=FW8FBL6232YUA8M7AB33BK3/D620r20b_00.kdz
Because LG has made some changes in its server settings, You can not use browser to download the firmware from above URl from LG server directly with Browser. Please check this guide on how to solve the blank page issue when trying to download LG firmwares.
To unbrick/Restore Your phone back to Stock, You need to download and install:
1) LG USB Drivers
2) LG Up Software
3) LG UP DLL file for your phone model