Nikon FG not working in A or P modes

[robert_bowring]

A friend gave me a Nikon FG camera. I cleaned it up and put new batteries and seals in it and got it to work. The problem is that it only works in the Manual Mode. In Auto  mode or Program mode the shutter speed does not change. The shutter speed LEDs in the view finder do change but the shutter always fires at the same speed. It sounds like it is stuck on the M90 manual speed. Any ideas what the problem is?

[John Seaman]

No answer but a couple of random thoughts. I think it would behave like that with a charged flashgun fitted, when the shutter would automatically be set to the flash synch speed. But I guess there's no flash fitted.

Another thought - if you remove the base plate you will see a circular electrical contact which turns with the advance lever, with wiping contacts. It may be worth cleaning this with contact leaner. I'm not sure what it does but it may be worth a try.

 

[rodeo_joe1]

I think it only fires at a fixed speed until the frame counter reaches frame 1. Could that be the issue? 

[John Seaman]

1 hour ago, rodeo_joe1 said:

I think it only fires at a fixed speed until the frame counter reaches frame 1. Could that be the issue? 

Of course!!! I don't know how I missed that as it's caught me out many times. A number of cameras from that era had a system whereby they shot at a fixed speed for the first three exposures or so after loading a film. This is because in auto exposure mode, the camera can set a very long exposure time in low light conditions, especially with the lens cap fitted and it seems like the camera has locked up. So your camera is working correctly. Good luck with it, nice camera.

[robert_bowring]

That is not the problem. I have gone past the first frame and the Auto and Program modes just don't seem to work. The shutter speed does not change in those modes. It does work in Manual mode. 

[John Seaman]

Oh right. Perhaps the system I described is stuck. I guess there is some kind of sensor or lever which "tells" the camera that the back was open. Could it be sticking? That's about all I can suggest.

[rodeo_joe1]

On 10/29/2022 at 3:18 PM, John Seaman said:

I guess there is some kind of sensor or lever which "tells" the camera that the back was open. Could it be sticking?

Yeah. I've had that happen too. The foam light-trapping can get gooey and stick the little sensor from popping out. It usually prevents the frame-counter from zeroing though.

A corroded or stuck switch on the frame-counter seems a more likely suspect. If it's dirt or corrosion, it might rub off if the switch is operated a few times. It might just need the frame-counter resetting and advancing past frame 1 a few times. Worth a try.