Nikon F3P (Press): Stuck mirror

A well-used Nikon F3P sometimes keeps the mirror up after the shutter is released. I suspect that it is due to resinification/a lack of lubrication.

This time I will not attempt a shortcut, but a repair.

To do this I will have to remove the mirror box, which is connected to the front part of the camera in a similar way to the Nikon F4. The mirror mechanism should be accessible there, which is where I suspect the problem is.

That should be the last repair on this copy; I have already replaced the hot shoe with ASA/exposure correction underneath, see

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I start next week.

Stay tuned

I'm sure you have checked this on your camera, but for others who may be tuning in...

When this has happened to me (well, to my camera) it was because the foam bumper strip had gotten guey. Easy enough to replace.

Engineers who specify urethane anything in a product should be hung, drawn and quartered, but only after they have been first whipped and keel hauled. Pour encourager les autres, don't you know.

Nicholas Lindan said:

I'm sure you have checked this on your camera, but for others who may be tuning in...

When this has happened to me (well, to my camera) it was because the foam bumper strip had gotten guey. Easy enough to replace.

Engineers who specify urethane anything in a product should be hung, drawn and quartered, but only after they have been first whipped and keel hauled. Pour encourager les autres, don't you know.

Click to expand...

Thank you, Nicholas!

It really should be the mirror mechanism that has become uncooperative. If I put the camera on the prism, the mirror stops halfway.

At least Nikon has learned and packed its F3 focusing screens for changing in small plastic boxes with a durable foam base.

The focusing screens for F and F2 sink into sticky, crumbling foam ...

Before I open the F3P, I will practice removing the front panel with the mirror box on a training F3. The F3 and F3P are largely identical.

I am in the fortunate position of having two partially disassembled and one complete, broken F3. Two of them are also potential LCD donors for replacement.

If anyone is interested in the technology of the F3, the repair manual explains all the components in detail with extensive descriptions. That was the time, 1980, when you could cover a top-of-the-range camera in 190 pages in depth.

There is an additional parts list for the F3P, together with the F3/T and F3 Limited, see below.

It will definitely be an interesting project, beyond the problem with the mirror, and one that I am very much looking forward to. The F3 is a legend

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Nikon F3 repair manual:



Nikon F3/T, F3P, F3 Limited parts list:

And I also have new spare parts for the F3:



This includes three complete electronic kits as flexible circuit boards, new and in their original packaging.

I don't know if everything still works, electrostatic discharges are always a danger, I hope the previous owner knew that too. At least there are three LCDs included:



But the collector does not touch it

Exploration: Removal of the front panel with mirror box of a Nikon F3

As I suspect there is a problem with the lubrication of the mirror mechanism on the F3 Press, I removed the front panel with the mirror box from a practice F3 that was already partially disassembled. The F3 is essentially identical to the F3P.

In order to be able to clean and lubricate it specifically, the mirror mechanism on the left and right of the mirror box must be visible.

I also wanted to gain experience before I put the screwdriver to my F3P.

If I make mistakes or do the wrong thing, it's better to do it here on my practice F3.

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The practice F3 with the top controls and left body cover already dismantled. Also the interchangeable viewfinder has been removed.

To disassemble the rewind crank and left body cover from a Nikon F3 Press (this is the camera whose hanging mirror I want to repair) see


The holder for the LCD with lighting and LED for the flash ready indicator has been dismantled. Here I had extracted the functioning LCD for a replacement.




The semicircular resistance track for ASA and exposure adjustment, on which the wiper (on the wheel above) moves.






There are retaining screws under the leatherette on the left and right of the front panel, so it has to be removed.

Patience is required here so as not to damage the relatively thin plastic that the glued-on leatherette is made of.

Mild solvents such as isopropyl alcohol to loosen the bond are pointless here, as the plastic is impermeable. So it has to be removed step by step.

The red bar - the hallmark of the F3 - is also made of plastic and breaks easily, so be careful when removing it.




Retaining screws are located in pairs at the bottom to the left and right of the bayonet, and at the side and rear below the viewfinder.

All of them could be loosened without any problems.




Potentiometers for settings and their connections on the board.




The cables have to be desoldered.

Here I separated them with the side cutters.

This is quicker for my purposes and I don't need the circuit board as a spare part.




Rear view




The ASA/exposure unit assembly does not need to be dismantled as I had assumed. It is enough to unsolder these two cables.




Now the front panel with the mirror box can be folded away from the housing. Both parts are still connected via a cable.




The left side of the mirror box with parts of the mirror mechanism.

Cleaning and lubricating the moving parts on the F3P could allow the mirror to run freely again.




The right side of the mirror box.




Back of the front panel.

Case with horizontal focal plane shutter made of titanium foil.




The silicon measuring cell in the bottom of the mirror box, viewed from the direction through the eyepiece.




These two levers are used to tension and release the mirror.

I am not yet sure whether the front panel should be removed with the shutter cocked or released.




The release magnet.




The clutch for the Motor Drive MD-4.

Here a rotten foam cover falls apart.




Overview

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Conclusion

• Disassembling the front panel with the mirror box on the F3 is much quicker than on its successor, the Nikon F4. A similar structure of the cameras with front panel and housing is visible.
• I still need to take a closer look at the coupling of the mechanics for the mirror to the housing. It is unclear to me what status the shutter must be in when removing it - cocked or released.
• The structure and connection of the ASA/exposure correction unit was a bit tricky when dismantling it. But only two cables have to be unsoldered to be able to remove the front panel. At least that is my assumption.
• Reassembling my practice F3 is the next step.

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All information provided without guarantee and use at your own risk.

There are detailed instructions for removing and installing the front panel in the SPT Journal May/June 1985.

Information in particular on the coupling of the mechanism, shutter and mirror box, which cannot be found in the repair manual or is not as detailed:

Everything is ready, tomorrow (CET) I will start with the F3P to fix the stuck mirror.

Stay tuned

Failure - but also something gained

Unfortunately it didn't work today.



I was able to remove the front panel with the mirror box on the F3P and lubricate and oil the moving parts of the mirror mechanism as far as possible, but then could not solve a problem on the way back.



But it was fun, I was able to get to know the F3 Press from the inside and the LCD remains in perfect condition, which is a valuable spare part for replacement. Of course, all the other parts will also be added to the stock.

Yes, it's a shame about the camera, but my pain is limited.

The F3P had a busy life behind it, it worked, but was already pretty worn out, as the following photos will show.

Extensive disassembly, cleaning and lubrication would have been advisable. With all the associated problems, including adjustment.

I hadn't planned for that

The snappy LCD was worth the sacrifice. I have a couple F3P bodies, one has a dim LCD, these cameras are beautiful. One can buy mint F5 bodies for less, but the F3P is beautiful! Thanks for the report!

mshchem said:

The snappy LCD was worth the sacrifice. I have a couple F3P bodies, one has a dim LCD, these cameras are beautiful. One can buy mint F5 bodies for less, but the F3P is beautiful! Thanks for the report!

Click to expand...

You are welcome!

I have a mint F3P in my closet. That saves me

I'll post some pictures of today's project.

I followed the disassembly instructions in the SPT Journal May/June 1985, which I have in print.

With better photo quality than in the excerpt, which is available as a scan:





The DE-5 viewfinder, which has a titanium cover cap and was made exclusively for the F3P, shows an eventful photographic life. This camera was used intensively.




The F3P is also sealed against moisture and dust.

In the picture you can see a stiff adhesive strip around the ASA/exposure correction unit, which served as a dirt trap.

This is also where the FRE (Functional Resistance Element) is located, the gold wipers of which can be seen in the picture above.

The wipers contact the curved resistance track below.

This is where settings are converted into voltage values that the camera's circuitry processes.






To loosen the two retaining screws at the front, the leatherette only needs to be lifted at the corners and not removed completely, as I previously assumed.

This saves you some work and damage to the leatherette, as it is firmly glued on.




This lever on the housing connects to its counterpart on the front panel. I ultimately failed at this one.

Here I am taking out the lever after loosening its retaining screw.




Done, I had to unthread the lever from its position, which took some time.




Removing the two upper halves of the housing after removing the controls is no problem.

Here the winding lever and parts of the shutter release on the right.






I cut through the rubber coating of the shutter speed dial. This way it can be easily removed and is not stressed when it is removed. The cut edges are almost invisible after gluing.




The retaining ring around the base of the lifting lever can be loosened using the spanner wrench.




After loosening the eight retaining screws at the front, sides and back, of the LCD unit on the mirror box and unsoldering a few cables, the front panel can be carefully pulled out of the housing.

Here I use the screwdriver as a lever for the first few millimeters.




Approximately 40 year old adhesive used to attach the leatherette.




Six cables have to be desoldered here.

The photo documentation will help with re-soldering later.




The front panel (below) is now free.

Milestone reached!

Four spacers fell out of the camera when I was dismantling it. I don't know where they are and I can't find any information about them in the service manual.

That's not good, because they could be used to adjust the front plate, which determines the flange focal distance (distance between the rear lens and the film plane). Blurring can result if the spacers aren't used.

I put sets of screws that belong together on labeled index cards for better orientation.






There is a challenge here when assembling.

The cable connects the aperture ring around the lens bayonet to the camera body.

The white gear at the top is coupled to the FRE. The repair manual explains exactly how to set this up.




The left side of the mirror box.

This is where I will lubricate or oil the moving parts.




The right side of the mirror box with the release magnet.






The amount of dirt in the camera is kept to a minimum.

The additional sealing certainly contributes to this.




When reassembling, I couldn't position the lever, that I had previously removed, correctly.

When screwing it on, I tilted the screw and damaged the thread. This means that the lever is crooked and blocked.

Game over




Spare parts remain.

And they are now rare

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Conclusion

• The coupling of the mechanics on the front panel and the housing is critical. Instructions are available in the SPT Journal. You should familiarize yourself with the situation in more detail beforehand than I obviously did.
• The spacers that fell out of the camera can play an important role in adjusting the flange focal distance. Or they only serve as washers for the screw connection. It's annoying that I can't find any information about this in the repair manual.
• A thorough cleaning and re-lubrication would have done the F3P good. Even if there is only relatively little dirt in the camera and there are still traces of lubricant. This is - with more in-depth disassembly - a larger project with the risk that the camera's settings will no longer be correct.

+++

All information provided without guarantee and use at your own risk.

Additional information

Nikon F3P Parts List

Nikon DE-5 Finder Parts Manual

Nikon F3 Repair Manual

FRE (Functional Resistance Element)


Nikon F3 Technical Manual

Of course, the DE-5 viewfinder and the MF-6 stop back are also valuable, as is the B focusing screen.

These things are sometimes sold at crazy prices.

Andreas Thaler said:

A thorough cleaning and re-lubrication would have done the F3P good. Even if there is only relatively little dirt in the camera and there are still traces of lubricant. This is - with more in-depth disassembly - a larger project with the risk that the camera's settings will no longer be correct.

Click to expand...

This excerpt from the Nikon F3 Technical Manual shows how Nikon adjusted the F3 after production in the factory.

That's another reason why I'm skeptical that I could even come close to achieving this at home on the kitchen table