do you have an external floppy drive you can check just to make sure the swim is good?

or just swap the floppy drive out with a known working one from another mac.

its just a standard auto inject sony 2mb drive.

Techknight discovered that swim's in the portable can go...

is your +5 +12 good?

That 12v boost regulator can get weak.

how are you powering it?  with a 6v AGM battery and the 1.5a portable charger?