Tutorial Nikon F3(AF): Replacing the LCD

[Andreas Thaler]

On the Nikon F3 and its versions, the LCD that is reflected in the viewfinder can fail partially or completely.

Corrosion of the LCD connections could be a cause, or the LCD sandwich no longer seals tightly; black spots can also appear that make the digits unreadable.

The only solution here is to replace it with an intact LCD from an abandoned F3. Nikon does not offer repairs or spare parts any more.


Replacement done by yourself

I'll show you how I recently replaced the LCD on my Nikon F3AF.

The process is not complicated, but it does require a steady hand and good eyesight/good visual aids.

Unfortunately, this did not solve the problem with a faulty display, I suspect a problem in the circuit, see

Post in thread 'Nikon F3 and special models: Care, service and repair'
https://www.photrio.com/forum/threa...s-care-service-and-repair.206327/post-2789828

But the process may be of interest to other F3 owners.

For the replacement, you need a

• replacement LCD from another Nikon F3, which has to be removed.
• Crosshead screwdriver 0 or 00 (ideally JIS)
• Small flathead screwdriver
• Tweezers
• Adhesive (e.g. Pliobond)
• Soldering iron and solder
• Magnifying glass or magnifying glasses
• Electronics cleaner or isopropyl alcohol

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The candidate with a faulty LCD display, a Nikon F3AF.

The LCD is built into the housing of the F3.

The display makes no sense. A shutter speed should appear here.

The left top cover with structure must be dismantled.

Use a screwdriver to block the rewind fork and unscrew the rewind crank.

The rewind fork can now be pulled downwards.

Please note that there is a thin washer on the axle.

The sleeve for the rewind fork can be pulled out by operating the lever for the backdoor release.

Completed

The retaining ring will be removed.

A retaining ring pliers as shown in the picture is ideal for this, but one or two screwdrivers can also be used. This is used to carefully pry open the ring.

There may be a foam seal underneath the cover plate, which is only inserted.

I take out the seal.

The spring for the backdoor release lever must be removed. Be careful that it does not escape or get in your eye.

Unscrew the backdoor release lever.

The three cables in the hot shoe …

… are desoldered.

Be careful, there is plastic all around, please solder without melting anything like what happened to me here.

It is important during later installation that the unit sits flat on the housing.

 

[Andreas Thaler]

The two screws will be removed.

The hot shoe can now be removed containing the ASA dial.

The transparent plastic nose underneath must then be inserted back into the recess above. Only then will the assembly lie flat on the housing.

Now remove the top cover of the case, it is held in place by three screws.

Done

The LCD housing is dismantled - three screws.

Two screws hold part of the flexible circuit board here. They will be removed.

There is a seal here on the F3AF.

To conserve it, I cut it open with a knife.

Now carefully pull the LCD housing upwards which is attached to the flexible circuit board.

The split seal no longer hinders this.

Now the LCD housing is free.

The flexible circuit board can withstand a lot, but I'm still careful. In particular, it must not be bent.

The LCD - the destination of this expedition - with the faulty display.

Please remove the battery before starting the disassembly. It is only inserted here for demonstration purposes.

With a box underneath, the LCD housing can now be put down without stressing the circuit board.

The housing cover is removed after loosening two screws.

The tab on the left is then inserted during assembly.

This is where the infamous red button for the LCD and ADR (Aperture Direct Readout) lighting is located.

To the right of this is the small gray piezoelectric element that is squeezed when the button is pressed and emits a voltage to the two contacts to the right of it. Then the tiny light bulb above the ADR lights up. If it flickers, a little electronic cleaner will help.

Be careful not to lose the piezoelectric element, it is only inserted.

There may be a small metal plate inserted to the left of the element. There is none here.

One of the connectors for the light bulb, which is located under the metal holder on the right.

This connector has a recess in the LCD housing.

The connector must not come into contact with the metal holder, otherwise the light bulb will be short-circuited when the red button is pressed. Then it will remain dark.

Important for later assembly:

The holder must grip the transparent plastic prism underneath flush and must not be placed at an angle. Otherwise the pressure on the LCD at the very bottom of the sandwich will be unevenly distributed and display problems or damage may occur.

Now the holder for the prism is removed, two screws must be loosened first.

The two connections for the light bulb remain attached.

Be careful, there are fine solder joints to fix the connections on the circuit board.

 

[Andreas Thaler]

The transparent prism directs the light from outside onto the LCD.

It lies on the display.

The prism

And we've already reached the LCD.

It's located on the gold-colored connectors underneath.

The LCD is fragile and I therefore treat it carefully.

Here I clean the two dark conductive rubber strips of the replacement LCD with electronic cleaner (or isopropyl alcohol). The conductive rubbers make contact between the connections on the circuit board and the LCD.

Be careful that the strips remain on the display when removing the LCD and afterwards.

Before I insert the replacement LCD, I also clean the contacts on the circuit board with electronics cleaner (or isopropyl alcohol).

The metal holder presses the prism onto the LCD.

Two rubber strips on the prism transfer the pressure to the LCD so that it makes even contact.

If the two rubber strips are no longer glued to the prism, this is done with glue.

Two tiny drops at each end, ...

… press down and let it dry briefly.


Now the replacement display can be mounted.

The LCD is inserted, the prism is placed on top, then the holder.

And the whole process is now carried out in reverse order until the F3 is complete again.

---

To protect the electronics in the open camera from electrostatic discharges, I work with a grounding bracelet and a grounding mat.

Since this is probably not part of the usual home equipment, here is just a reminder to pay attention to this topic.

Electrostatic discharge - Wikipedia

en.wikipedia.org

 

[Andreas Thaler]

Nikon F3 Service Manual

Nikon F3 factory service manual

learncamerarepair.com

Nikon F3/T: LCD replaced

A project that has occupied me for years without being able to tackle it - for lack of a replacement display and know-how. Now it's implemented 😀 With my most beautiful F3/T (never used before), I had to watch the LCD display in the viewfinder slowly but steadily disappear. At first, only...

www.photrio.com

+++

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

 

[Andreas Thaler]

Some statistics

Of my twelve F3s,

• one has a faulty display,
• two have faded but still easily readable LCDs,
• all the others have flawless displays,
• and all work (except for one that only triggers on the Motor Drive MD-4).

I think that speaks for the durability of this legend.