I had the exact same issue with my model 1 a while back. There's a ribbon cable that connects the Drive to the actual SCD hardware inside the case that comes loose pretty easily, but I was able to snap it back on, and get a normal bootup after that.

...unfortunately, I was so excited about it that I manually closed the disc drive as I was reassembling it, quite possibly leading to the all-too-common constantly ejecting drive issue, so I swapped one issue for another :P