If you are looking at a schematic PDF of this board, pay close attention to the Block Diagram section. It will show you exactly how the 12V power enters, is stepped down by the DC-DC converter, and distributed to the Gate Drivers. This is the most valuable part of the documentation for troubleshooting.
. While a single standalone PDF datasheet or "paper" for this specific board is not widely available to the public, the board is documented across various parts catalogs and technical repair forums. Technical Specifications and Compatibility t-con mdk336v-0n pdf