Hello, Some days ago I bought a Nikon F4S. I think there's a problem with exposures modes other than A or M. When using it in shutter priority mode, the alert red LED blinks after each shot. It's located near the film rewind knob. It's then impossible to take another picture. I have to shut down the camera. If I stay in shutter priority mode and take another picture, the red led blinks again. However, if I switch to the A mode, the camera works correctly. That red LED blinks when there's a problem with the film advance or when the camera cannot set the aperture of the lens. Since I can take pictures in A mode I think there's no problem with the film advance. Therefore I think the camera cannot set the lens aperture when taking a picture in S mode. I tried several lenses : 50mm AF-D f1,8, 24mm AF-D f2,8, 35mm AF-D f2. I get the problem with all of them. What's your opinion ? Do you had such a problem with a F4 ? How does the camera set the aperture of the lens? Is it with the lever located on the left side of the mounting flange ? It seems to be ok on my camera. The electrical contacts are clean. The seller told me he always used the A mode and wasn't aware of that problem. He's ready to take back the camera or reimburse a fraction of it price if I decide to keep it. For the moment, I shot 1 roll of film (staying in A mode), and another one is in the camera. I plan to make a lot of tests with the camera when I'll have finished that roll. Thanks for your opinion/advice ! Nicolas, Paris.