The Sony AV-3600 service manual was what I needed for the repair of this unit
Thanks for the good service
Dave
Text excerpt from page 1 (click to view)
TX-28/25/21MD3C 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.