The file you are looking for relates to the universal smart LED TV motherboard. This specific firmware is designed for a screen resolution of 1920×1080 with a REF48 (likely 48Hz or a specific panel reference) configuration.
On many models, the indicator light (LED) on the TV will start flashing rapidly, indicating the software is being written. Download MT5507 PB801 1920Г—1080 REF48 USB part4 rar
Ensure the power does not cut out during the update, as this can permanently "brick" the motherboard. The file you are looking for relates to
Only install this if your TV panel is exactly 1920×1080 . Installing 1080p firmware on a 720p (1366x768) screen can cause a distorted display or a "black screen". Ensure the power does not cut out during
Move the extracted .bin or .img file to the root directory of the USB drive. Do not put it inside any folders, or the TV will not find it. 2. Installation (The "Auto-Update" Method) Most MT5507 boards use an automatic bootloader update: Power Off: Unplug the TV from the wall.
Sites like Kazmi Elecom often host these specific universal board files if you are missing any parts.