I recently purchased on eBay a Pentax 645N. It looked pretty new in the box. The only thing it is does not work. It has a fast 2.8 lens. The batteries are Lithium and new. The battery indicator light blinks no matter how much I clean the battery connections. The battery holder tested as 9v yet flashes. The camera makes a whine when I press the shutter and then stops, with indicator flashing. I'd like to see if there is a quick fix. Thanks! Jim M.