Help!, my Tefal "smartclean" deep fat fryer has broken. I've looked inside and it looks pretty simple. I have checked most of the bits (switches, element, etc) for continuity and all are OK apart from one thing that looks like an overheat cutout. It appears to be a small plunger on a spring, aimed at the base of the cooker, If I press the plunger against the spring pressure, it makes, otherwise in is an open circuit. I noticed what looked like solder beads around the base of it and wondered if this was anything to do with it. Anyway, I'm now at a loss and the kids are whining about not having any chips, so I need to fix it. Any ideas?