I think, it will be interesting to look what is inside at the “white” Canon L-lenses series. Partly because they are made best of all, they have really many metal parts and they are the most expensive.
Today there is a short digression to interiors of Canon EF 70-200mm f/4L USM, we were provided Shreds by Skibitsky.

It was impossible to find the disassembling diagram of  the Canon EF 70-200 f4 L IS USM lens, I suggest to study the Canon  EF 70-200 2.8 L IS USM diagram, because all of them dismantle on approximately the same scheme.
I couldn’t believe in the first moment that such big green board is located in a lens and some third-party controller for check of a lens thought it.