The "corrosion" would have to be severe to require replacement. If the
camera was not exposed to unusual conditions, you likely have a unit that
was not cleaned or sealed properly from the factory.
Forty years ago, I had a Nikon zoom lens for my FT-N. It started growing
green stuff on the inside. It was returned to Nikon (I was in the Navy in
Japan at the time) and Nikon rebuilt the lens, apologized, and sent the as
tested tech specs for the individual lens, showing that it (after repair)
exceeded the minimum (advertised) specs by quite a bit. It was a lot
sharper after the repair, and the zoom function was much smoother.
> As a follow up to my prior POST in Aug 2007
>
[quoted text clipped - 16 lines]
> Hope this helps someone else.
> -John