Miele W800 door switch not working?

I have just changed the dampers on my Miele W800 - thanks for the excellent information - but the machine won't switch on!
The fuse is ok & when I press to start, the "on " light comes on for millisecond!
The door will only open using the manual pull.
This all suggests to me that the door switch has got out of line when I had to undo the 3 bolts that hold the front in place.
Any ideas how to fix it...otherwise I will have to disassemble again & see if that fixes it! The dooerseal seems properly in place