HP (sony made) floppy drives have the same problem.
They stick part way
open and don't eject the disk. If you pull the disk out, you WILL rip the
top head off of a double sided drive. Never take a disk out or put a disk
into a partially open HP floppy drive. Take the drive out and clean the
old lube off so that it opens properly.
This problem apparently has two stages, fix by cleaning, and waited to long
and damaged the motor which now needs to be replaced. The notion of a
"weak" motor is a bit hard for me to grasp, but I have run across several
cases with motors and solenoids where it indeed seems to be true.