Because this is "part03," you cannot use it alone. You must find and download all other parts of the set. If any part is missing, the firmware extraction will fail with a "corrupt archive" or "unexpected end of archive" error.
Do you have the of this archive (part01 and part02), or do you need help locating a complete single-file download for this model? TV android there is no light standby board TP MT5510S PB803
Before attempting an installation, physically verify the model number on your TV’s green motherboard. Installing firmware for a different board version (e.g., PB801 instead of PB803) can "brick" the TV, rendering it unusable.
.rar archive, which requires all associated parts (e.g., part01, part02, etc.) to be downloaded into the same folder before extraction can succeed. Key Considerations for Downloading
AKAI AKTV2415 (specifically the REF50 variant).