A paper service manual is useful only if it matches the complete model code and hardware revision. Unlike a user guide, it is intended for diagnosis and repair.
It may contain schematics, connector layouts, test points, adjustment instructions, replacement procedures and fault-flow diagrams. At a workbench, a printed page also leaves room for notes. A technician can circle a connector, record a voltage beside a rail, and mark each completed check without moving between software windows.
