Excelent scan job. It's a fully detailed service manual of this model.
Text excerpt from page 16 (click to view)
1-4. Usage of the Extension Board
6. With the eject levers 2 and rails opened, insert the plug-in board whose operations are to be checked along the rails of the extension board and push it into the connectors.
9. Open the eject levers 1 of the extension board in the direction of the arrow.
Eject levers 2
Eject lever 1
Rail
Extension board
Eject lever 1
(illustration of the HDS-X3700)
Plug-in board Rail
(illustration of the HDS-X3700)
10. Pull out the extension board from the unit. 11. Attach the plug-in board, wiring terminal drop-safe assembly, and front panel.
7. Adjust the plug-in board or check the operations of the plug-in board. 8. After adjusting or checking the operations, push the eject levers 2 of the extension board in the direction of the arrow and pull out the plug-in board from the rails of the extension board.
