Schematic in PDF form for the X51C, with T12C added in the name, which appears to be a related project or board code but is not explained further. The file is about 1.58 MB and lists no revision. Read it with any PDF reader and search for net names to move between pages quickly. Repair technicians use such diagrams to follow power rails, check regulator enable signals and identify components involved in no-power, no-charge or no-display faults. Verify that the board code on the PCB matches the one in the schematic title block.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @alischematics. Enginerys does not host this file.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.