PDF schematic for the Lenovo B490 laptop, roughly 1.95 MB. The name omits the motherboard number and revision, so read the board code inside and confirm it against the PCB before working from the drawings. It is useful for diagnosing no-power and no-charge faults: following the DC jack and charger circuit, checking always-on and main rails, and locating the EC, SPI flash and connector pinouts. Open it in any PDF reader and use search to jump to specific nets or reference designators.
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.