Will not run after a few seconds

My kenmore dehumidifier will die after only a couple of seconds. After leaving the unit unplugged for a while it will run for around 10 - 20 seconds. During this time the overflow switch works fine, as do the other controls on the unit. Once it stops working it is totally dead - the light will not come on and none of the controls do anything. This is repeatable, if I leave it unplugged for a while again it will start up and then die.

I have cleaned the filter and brushed the fins.

Any suggestions?