The matching transport felt unexpectedly heavy particularly against being relatively empty inside. Cause for the hidden mass had to be that additional steel plate which reinforces the bottom of a rather thin-walled chassis.
Unbolting the black CD tray…
… revealed the expected twin-belt drive details.
The spindle and laser head mount to a visco-elastically isolated sub assembly for some up/down give.
With the CD tray remounted, I took two more shots of the power supply…
… and output board.
Then I re-attached the door trigger cable to the main board and remounted the chassis cover with its dark Perspex sliding door.