Are you trying to using a programmer, or just looking to update the software via a USB stick?
Go to Menu > Help > System Information to see your current version. Download VST59 PA506 Panasonic 24D400DX Dump rar
Loading a dump file requires a specialized hardware programmer (like the RT809F or RT809H). Incorrect firmware can permanently damage the board. Official Firmware Update Alternative Are you trying to using a programmer, or
You can find spare motherboards or technical files on sites like AndroidFixCell or LED LCD TV Spares . Download VST59 PA506 Panasonic 24D400DX Dump rar
If your TV still powers on but has software bugs, it is safer to use the official update method: