HI Mamashep, so glad that you have managed to fix the problem.
I mentioned that I had a few problems with one of my Bernina overlockers, and I happened to go on an overlocking course just after I had purchased this, and it was playing up intermittently, so once the course itself had finished the engineer was called into the sewing room and he prodded and poked around and adjusted something and it has been perfect ever since. The probe on the door just has to fit into the other part on the other part of the machine otherwise it will not work – I think this is part of the safety mechanism. Just think how many times the doors are opened for threading up and for cleaning, and whilst they shut they still have to be properly aligned.
These machines work at such a speed and when they work they do a fabulous job, however when something goes wrong – which can happen occasionally, then they do cause us all sorts of anguish – we have just got so used to using them, and are lost without them.
So glad that you have saved yourself a lot of money.