The swivel on the mains cord is held back by 2 screws also easily accessible when the arms are separated

I bend the small pickups in the white part a little bit to make then just a bit tighter. (I dont know if this was the loose connection, but after assembly the blue light signalling heating started working again)

Caution, the parts inside carry (in my case 230 Volts) So checking for loose connections while taken apart should be done with an Ohm Meter or similar.