Aquilegia

It wasn't pushed fully home Mickey2, once it was and then tightened it prevented the cog from revolving which is what I needed.
At the moment it's all hunkydory.

OurWorkbench

Congratulations!!

"The pin that goes down the centre of the unit doesn't have a flat end as shown in pics I've seen, I suspect it may have snapped at some point."

Just as long as it releases the tension discs when you raise the presser foot, it doesn't have to have a smashed end. Some have used other things the same length and diameter.

Now, just enjoy sewing with your machine.

Janey - Neat people never make the exciting discoveries I do.

pocoellie

I have to agree with Cari, take it back to the shop that "serviced" it, and tell him either fix it as he should have before telling you it was "ready" or give you your money back, then find a reputable person to service it.