Another common floppy drive problem is for the disk detection sensor to get dirty. What will happen is that the drive constantly or randomly thinks a disk has just been inserted and will try to read it as such. Obviously this makes disk operations unstable. It’s a very easy fix, fortunately, compared to realignment.
Just inside the drive on the left-hand side you’ll see a little black post. It's supposed to move freely up and down when a disk presses on it. Clean it with some isopropyl alcohol via a q-tip/cotton bud until its movement is fluid again and you should be back up and running.
You might need to take the 1200’s case off to get clear access to the post. If you’re feeling braver, you can also take the top case of the floppy drive off for very easy access and other cleaning opportunities short of realigning the drive.
Also, you’ll get a much better video signal from direct SCART as opposed to SCART-to-composite, but if all you need is any sort of display then you’re all set.