Circuit diagram in PDF form for the X55C, with an additional RG suffix whose meaning the name does not explain. The file is 1.39 MB and opens in any PDF viewer. A technician can use it to follow the power-on sequence, check standby and main rails, trace charger and USB circuitry, and read component values when replacing parts. The RG tag may refer to a board variant, so compare the title block with the markings on the motherboard before working from it.
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 @cyberlanelectonik. 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.
Any PDF readerSumatraPDFFirefox / ChromeFlexBV (links PDF to boardview)