As mentioned on the thread abv
Just wondering how many of u had the same problem.?
i had sb800, and various non nikon flashes, none of them gave me problem as the sb900.
A check with friends some also had send in for servicing for the same problem.
The diagnostic check from the service centre took only few mins just mere cursory glance with a built in led magnifying glass inside the battery compartment. They declared thw 900 unserviceable without even opening up for further checking.

This is nikon service centre way of working?