Yes, managed to use a screwdriver to open the door.
The oven had been screwed into the kitchen unit.
The owner found the receipt and I managed to activate the warrantee. Then I could get a warrantee visit.
The fixer came on time today and not needing to diagnose the fault could just replace the part and so only needed to take 14 minutes.
He left the old one so I will be able to try to open it and see what has gone wrong.
