Im having exactly the same problem...I have read a few things about the shiver mode meaning that when the ghds get below a certain temperature they will not work to protect them from condensation....the suggestions I read have been to try heating the plates up with a hair dryer first or keep the ghds in a warm place for a while before trying to turn them on again. However it could also mean a loose connection in the wiring.
Rachael bell, November 2009
