Help with Autofocus failure Nikon F4

Started 5 months ago | Discussions
mnassal New Member • Posts: 2
Help with Autofocus failure Nikon F4

The “X” indicator is on all the time in the viewfinder.

Does not matter which lens, what focus mode. It stays even in manual focus mode.

All the lenses work fine on my F90 and 2 F80 and my digital cameras.

When the camera attempts to focus it just goes back and forth without locking on a focus point,

I cant find anything on it the repair manuals or message boards.


bokesan Contributing Member • Posts: 553
Re: Help with Autofocus failure Nikon F4

I've not experienced such a problem, but my guess would be mechanical damage or misalignment in the phase-detection system. If you lock the mirror up, does the small AF mirror on the back of the mirror fold correctly, and does it look undamaged? If you have a small mirror and a light, do the AF sensors on the bottom of the mirror box look clean?

Is this a new problem, that is, did the camera work at one time?

D Lynch Veteran Member • Posts: 5,340
Re: Help with Autofocus failure Nikon F4

Have you cleaned the contacts on the camera body and lenses?

Wipe them first. Consider using a pencil eraser and abrade the contacts carefully. Wipe them clean.

And do the same with the battery and body contacts.

I hope this helps...

I used to do this with my F3HP's as a preventive measure.

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