Sounds to me like it's the switch that detects a floppy disk being present. It's probably dirty and needs a clean. If you insert a disk and then type "diskchange df0:" into a CLI does it help?
When booting the switch sounds like it's stuck and the Amiga thinks there is a disk. It tries to read the "imaginary" disk with no luck and gives up. Later when you put a real disk in the drive the change is not detected and the Amiga takes no notice.
|