Firmware for this specific chassis is often hosted on specialist technician forums rather than official manufacturer sites.
The MT5510S board generally uses an "auto-update" method when it detects a firmware file during boot: Download MT5510S PB802 3840x2160 SAMTRON REF80 part7 rar
: Extract the .rar file (like the "part7.rar" you mentioned). Place the resulting firmware file (usually named allupgrade_5510_8G_1G_...pkg or having a .bin extension) directly into the root directory of the USB drive. Do not put it inside a folder. 3. Installation Procedure Firmware for this specific chassis is often hosted
: Completely disconnect the TV from the wall outlet. Download MT5510S PB802 3840x2160 SAMTRON REF80 part7 rar