I think that it's the cable. I'm getting everything lined up, though. First order is to get a power adapter. Second is to disassemble the iBook, then test to see if it's loose cabling or some easy fix that won't need a replacement. Then order parts as needed.

The goal is to disassemble and reassemble the iBook exactly once more, a final time, and make the mean time between those two points as short as possible.

I think that it can be done.