Official manufacturer websites like Panasonic Support usually provide "update" files (via USB), not raw "dump" files. A "dump" file (often in .bin format inside a .rar archive) is usually found on technician-focused forums or spare parts sites.
If your TV still powers on but has software bugs, it is safer to use the official update method: Download VST59 PA506 Panasonic 24D400DX Dump rar
Copy the file to a FAT32-formatted USB drive, insert it into the USB 1 port , and follow the on-screen prompts after turning the TV on. Download VST59 PA506 Panasonic 24D400DX Dump rar
You can find spare motherboards or technical files on sites like AndroidFixCell or LED LCD TV Spares . Download VST59 PA506 Panasonic 24D400DX Dump rar