Help with my sunkko 709a

My sunkko 709a’s soldering function doesn’t work. When I flick the switch, the red light for the solder dial does not turn on and the tip does not get hot.

You need to turn on the spot welding switch aswell! => flick both switches to on and it will work

My Sunkko 709A stopped working one moment after switching the switches on simultainously, I guess it doesn’t like that? Something something inrush currents?

Anyho it just light’s up the green and red main switch but nothing else
Took it apart, be careful the orange current knob is sitting on a lip on the outside cover ( the transparent ring) and on the inner side it is being held onto ther PCB via soldered varistor that is Stuck in the orange knob - broke the varistor’s pcb while prying it out as I couldn’t not see it, dunno how they assembled that