This is exactly the service manual I needed.
Complete with all schematics, partslists, PCB layouts and alignment instructions.
This manual covers both the T-4970 en T-488F Onkyo tuner.
Text excerpt from page 1 (click to view)
TX-28/25MDT3F Service Manual
Safety Specifications Parts List Service Information Adjustments Self Check Service Hints Mechanical View Disassembly Location of Controls Waveforms PCB Views Schematic Diagrams Block Diagrams
Service Support Service and repair of this product is supported by Panasonic's LUCI interface. This interface provides a link between the TV and a standard PC to allow a number of diagnostic and control functions to be performed. For more details contact your local Panasonic company.