I have a beautiful Bertram light meter (reflective), but unfortunately it doesn't work. The needle just bounces between 0 and 2. I was thinking about opening it up and poking around inside, but I don't know anything about how the guts work in a light meter. Does anyone have any experience with this, or know of a link that points in the right direction? I'd rather do it myself than send it out, if at all possible. Thanks.