This customer never had a problem for 5 years, then all of a sudden it starts sparking inside the vent area. I took out the control panel and found the main relay board was never attached to the wall but was sitting on the metal flooring of the control area. Everything went fine until moisture from the vent tube dripped down onto the metal flooring and shorted the board.
This came straight from the factory.
See the pics.
If it wasn't for the moisture dripping towards the board, this would never have been a problem