Thank You for all comments.
I posted the problem on Nikon forum and i got help from one senior member.
It ended that aperture follower pin on camera was damaged,exactly broken spring connected to follower.
I bought another F-801s and everything seems to be working as it should.
Going to start shooting Black and White film,we will see.Last time i did that was 30 years ago with Russian made FED-5:)
Reply To: Nikon F-801 ,aperture not changing in M or A modepeterzoch2021-06-27T17:19:35+00:00