Lenovo B490 laptop schematic in PDF format, 1.95 MB in size. The name gives the model only, with no motherboard number or revision, so read the title block inside to find the ODM project code and compare it with the marking on the PCB. A circuit diagram like this lets a technician follow the power path from the DC jack and charger to the CPU, memory and chipset rails, check enable signals, and pinpoint which component sits on a rail that measures shorted. Any PDF reader with search will open 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 @schematicslaptop. 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.