Epson Stylus Pro 9900 - Correct with the Pins in These Holes; Incorrect with the Pins Not in These Holes

Pro 7900 and 9900 Field Repair Guide 10/6/10
SpectroProofer Troubleshooting Printer Component, Software Item, LCD Display, Printer Button Page 247.
7. Install the ILS Head into it’s correct position.
8. Plug in the 2 cables to the ILS Head.
9. Verify that the ILS Head is still seated correctly.
10. Place the SpectroProofer on the Printer.
11. Connect the USB Cable from the Printer to the SpectoProofer.
Correct with the Pins in these Holes.
Incorrect with the Pins not in these Holes.