While a single direct .rar link isn't hosted on official consumer sites, the following resources provide the necessary technical data for this hardware: : Detailed technical data for the LG Display LC420WUN-SCA1

If you are unable to find the exact .rar file for this specific board/panel combination, technicians often use these methods:

: General repair information and schematics for the LC420WUN series are often available via technician communities like Elektrotanya .

: If the TV still boots, check for a "Software Update" option in the service menu.

: For modern Artel updates, the company provides a dedicated Firmware Updates page, though it primarily covers newer DigiLink and InfinityLink modules. Technician Steps for Firmware Recovery

Finding a direct download for the firmware (specifically the JUG7.820.1340 mainboard and LC420WUN (SC)(A1) panel) typically requires accessing specialized technician databases. Available Resources & Technical Documentation

: For "dead" units, the firmware is usually flashed directly to the SPI Flash chip using a programmer (like a CH341A) and a .bin file extracted from a working board of the same model.