Brother Intellifax 775 Paper Cover: How to put it back on machine?

Last night my downstairs neighbor called me and asked if I could come down and try to clear a paper jam in her fax machine. Why she called me is beyond me, because I am clueless when it comes to electronics, but I went down anyway, to see what I could do.

It was a Brother Intellifax 775.

It had a trapdoor like plastic lid over the paper, which looked like it could be lifted out to give better access. I wiggled it and sure enough it came right off.

I cleared the jammed paper. But then I was unable to get the paper cover back on. And the machine won’t work without it. It looks like there may be a little switch that detects if the paper cover is in the correct position.

I’ve tried Googling for a Brother help forum, but haven’t come up with anything so far.

I’d be grateful for any ideas you might have on how to solve or get help solving this puzzle.

See page 79 of the manual.