You can find spare motherboards or technical files on sites like AndroidFixCell or LED LCD TV Spares .
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. You can find spare motherboards or technical files
Visit the Panasonic Global TV Download Page and search for the model TH-24D400D/DX. Download VST59 PA506 Panasonic 24D400DX Dump rar