Dell Vostro 3300 schematic in a 1.05 MB PDF. The name lists only the model, without the ODM board number or revision, so open the title block to identify the mainboard and compare it with the PCB silkscreen. Dell notebooks are typically built by ODMs whose numbering appears in the drawing. With it a technician can trace rails from the DC jack, check charger and regulator circuits, follow enable and power-good signals, and find which components share a shorted net.
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.