[JRTJH]

If the fan was stored in the closed position, the lid may have "stuck" to the rubber gasket that seals the lid. You might simply have a situation where the lid motor can't open the lid and the fan motor won't turn on until the lid is open. Before "tearing into things" you might want to get on the roof and use your fingers to help the lid motor get the lid to start moving.

While this may not be your problem, it is something that "ought to be done" before disassembling the fan, looking for failures.