Panasonic Service Manual. Sequential Switcher: WJ-506, 506A, 507, 507A, 510, 510A. Cover: Canted angle view of three models and a chart of Specifications. Inside, booklet contains the following sections: Introduction, Accessories, Names of Operating Controls and Connectors, System Connections (with Two Sequential Switchers and with Time Lapse VTR (NV-8030)> diagrams), Circuit Description, Block Diagrams, IC, TR, Diode's pin arrangement, Schematic Diagrams, Packaging, and Replacement Parts List.