A tutorial on the aperture control problem with the Nikon F4 has been published on Learn Camera Repair.
In this case the aperture on the F4 no longer works properly.
Author Vladislav Stanimirović goes much further in troubleshooting the problem, servicing the removed aperture control and also working on parts in the mirror box.
A highly interesting article, illustrated with numerous photos, which is dedicated to the topic on 46 pages and provides detailed explanations.
An outstanding work in a field where documentation is scarce.
