Nikon MD-4 repair

[richardHaw]

https://richardhaw.com/2017/06/24/repair-nikon-md-4/

Hope this helps you! It was helpful to a friend of mine. his MD-4 was dead but was brought back to life.

 

[BrianShaw]

I'm not having this kind of problems at the moment but appreciate knowing about new resources. I was not aware and thank you very much.

 

[richardHaw]

thanks! these are tough but like my friend's MD-4 it will conk out without warning at times.

 

[fdonadio]

I happen to have a bad MD-4 right now and will try these techniques before I send it to a repairman.

Thanks, Richard!

 

[richardHaw]

I happen to have a bad MD-4 right now and will try these techniques before I send it to a repairman.

Thanks, Richard!

Great! be careful!

 

[fdonadio]

Great! be careful!

I finally took the plunge and tried repairing my MD-4. It was plain dead: no battery test, no rewinding, no signs of life at all.

I cleaned the contacts inside the battery compartment and also the coils in the battery holder, that were a little corroded. Tested and it still looks dead.

I did an almost full disassembly and found a handful of broken wires, which I resoldered, following the diagrams on the service manual. There are detailed drawings of the PC board and all the wires are color-coded, so I am pretty much convinced I did it right.

While at it, I cleaned the gears next to the motor with naphtha (lighter fluid) and lubed the shafts and some small moving parts with light clock oil. I got lots of black gunk out of it.

Reassembled everything according to my disassembly notes and the manual and tested. Battery indicator works. The right LED lights up when the trigger knob is moved to S or C and won't go off. I checked the frame counter and the end-of-roll sensing contacts, which are not shorted. Everything else doesn't work.

I didn't reapply the leatherette and am thinking of trying once more, but I am not very hopeful.

If anyone has any idea of where to look first, I'd be happy to know.

Cheers,
Flavio

 

[shutterfinger]

I trust you used rosin core solder, did not bridge any contacts when soldering. Do you have access to a VOM? (volt/ohm meter)
What does the battery holder read with fresh batteries? Should be greater than 1.5 * the number of batteries.
With the VOM set to ohms measure the motor drives battery contacts with the switch off, on, and advance button pushed. Off- infinity resistance, on- at least 10 k ohms, advance button pushed - 100 ohms or less. Reverse the leads at the battery contacts and test again.
Nikon battery holders go bad and the batteries will read correct voltage but not supply sufficient current to run the drive.
There is a good MD4 on ebay USA for a reasonable price and a few non working ones for cheap. Skip the price gougers.

 

[fdonadio]

I trust you used rosin core solder, did not bridge any contacts when soldering. Do you have access to a VOM?

I do have one, but didn't test the resistance between the battery compartment contacts. Just tested for shorts using the "beep" setting.

I am pretty lousy with electronics, but I can solder and interpret diagrams. I am gonna check the resistance values and get back. I should also read some other parts of the service manual.

Thank you very much for the tips!

 

[fdonadio]

What does the battery holder read with fresh batteries?

It reads 12V, but this VOM is not precise enough. It's a model more oriented towards electricians, with that clamp-type ampere-meter. I have a better one at the office. I'm gonna bring it home tomorrow for some more tests.

With the VOM set to ohms measure the motor drives battery contacts with the switch off, on, and advance button pushed. Off- infinity resistance, on- at least 10 k ohms, advance button pushed - 100 ohms or less. Reverse the leads at the battery contacts and test again.

No matter which way I measure, it's infinity. It seems some really important part of the circuit is open. I'm gonna have to check all the blue and red wiring. Maybe the ribbon cable is bad too.

Nikon battery holders go bad and the batteries will read correct voltage but not supply sufficient current to run the drive.

Yea, I see one of those coiled terminals is significantly corroded. It still conducts energy, but it sure has seen better days.

I really wanted to make this one work, but it's going to be a tad difficult.


Cheers,
Flavio

 

[shutterfinger]

The motor drive may have to be connected to the camera or have pins connected to get it to test correctly/work.

 

[fdonadio]

The motor drive may have to be connected to the camera or have pins connected to get it to test correctly/work.

Yea, I know which pins have to be shorted, but rewinding should work without shorting them. And it doesn't.

Maybe ill just get a good one.

 

[skahde]

Time to pull up this topic: I just acquired an MD4 in very nice condition which, thank god, is working flawlessly together with a fully working camera.
But there is one minor thing: The battery-compartment is not sitting snug inside in the MD but can be pushed in by about a half to a full mm or 32th to 16th of an inch.
The inside of the compartment and the insert look clean and perfect. The latch connects positively and is not worn.
To me this looks like the latch, holding the battery-insert in place has moved outword over time.
Honestly it is just cosmetics as the insert makes perfect contact but if anyone nows a method to easily adjust the position of the latch, I'm all ears and say thanks in advance!
This is about the worst it looks:

 

[Andreas Thaler]

This is the slide for locking the battery holder. It is attached to the battery handle with two screws and can be adjusted in two directions.

 

[Andreas Thaler]

The handle can be separated from the Motor Drive housing loosening three or four screws. A small piece of leatherette must be removed from the bottom.

The handle is then only connected to the housing via a flexible circuit board.

It's all very robust and solidly made.

Nikon MD-4 Motor Drive: Issues with rotary switch and rewind resolved, cleaning

The MD-4 on my table has been through a lot. It accompanied the F3 Press on which I replaced the exposure compensation wheel. What's even more pleasing is that it works on the F3 Press and only has minor problems: The rotary switch around the trigger for setting the motor operating mode (L...

www.photrio.com

 

[skahde]

I'm impressed and draw my hat! That is all I need to fix it and exceeds my wildest expectations!

Many thanks!

 

[Andreas Thaler]

I'm impressed and draw my hat! That is all I need to fix it and exceeds my wildest expectations!

Many thanks!

Gladly!

Let us know if it was successful

 

[skahde]

Just to get this straight, steps are:
1. remove the three (in my case I see three) scews inside the drive, behind the grip.
2. Carefully peel away the leatherette under the grip. As I take if from the pictures, partially removing it from the rear should suffice.
3. The grip is only connected via the circuit board and there should be enough room to loosen the screws holding the slider just a bit, adjust, fix again.

As always take pictures for reference generously. Saves more time later than it takes.

Sounds straightforward, I guess the scews holding the slider just have loosened at one point.

 

[skahde]

I tried to remove the grip and after removing the above mentioned screws inside the compartment and on the right side of the motor I could move the grip away from the body at an angle but not enough to reach the screws to adjust them unless a bent screwdriver was at hand. I figured that this may not be the intended way to do it and took a closer look at the parts in my hands. And indeed: Access to the adjustment-screws from the battery-compartment is only covered by two small black metal-disks which can be easily peeled away and glued back later.

So just in case, someone needs to do this in the future: Remove the disks, loosen the screws a bit, wiggle the catch for the battery-compartment as much in or out as desirable. Fix the screws and redo until you got it right. Then tighten the screws and glue the disks back on.

In my case, I unfortunately managed to kill the motor in the process. Maybe I broke a connection when separating the grip from the body or I flooded it with too much lighter fluid when peeling off the leatherette from the bottom of the grip. I may look into this at a later point as the motor is to nice to discard it and it's also against my standards for myself to let the story end this way. At least I have to give it another serious try and really get to my limits of competence before I give in.

 

[Andreas Thaler]

@skahde That's interesting about the two disks, I didn't have to remove them.

I'll take another look at that when I continue with my MD-4.

If you need spare parts, including the motor, I'm well supplied.

 

[skahde]

@skahde That's interesting about the two disks, I didn't have to remove them.

I'll take another look at that when I continue with my MD-4.

If you need spare parts, including the motor, I'm well supplied.

Thanks, Andreas for the kind offer! You certainly don't have to remove the disks if you completely separate the grip form the body of the winder as you did above. In the process of doing so, I noticed the disks. Nikon obviously thought about the occasional necessity to readjust the catch and provided an easy access to it via those two holes.

 

[coll]

Hello
Fresh enough like my problem as i bought a problematic MD4 from a bad seller on ebay.

Well, it shoots continiously when i press the shutter c or s position and it doesn't stop after,even if i stop pressing.
It is doing the same non stop even if i try the tester!
Finaly the only way to stop it is to use the rewind button.

Also the counter sticks to number 4 frame, (and the shutter continius to photo with no stop)but this is not so important for me as the maim problem.

Do you think i have any hope with opening around shutter button or contacts,or to buy another ?

Thanks a lot

 

[Andreas Thaler]

Hello
Fresh enough like my problem as i bought a problematic MD4 from a bad seller on ebay.

Well, it shoots continiously when i press the shutter c or s position and it doesn't stop after,even if i stop pressing.
It is doing the same non stop even if i try the tester!
Finaly the only way to stop it is to use the rewind button.

Also the counter sticks to number 4 frame, (and the shutter continius to photo with no stop)but this is not so important for me as the maim problem.

It could be a contact error or dirt in the frame counter, which is not particularly well protected.

What does the MD-4 look like, does it show any significant signs of use?

 

[BrianShaw]

Hello
Fresh enough like my problem as i bought a problematic MD4 from a bad seller on ebay.

Well, it shoots continiously when i press the shutter c or s position and it doesn't stop after,even if i stop pressing.
It is doing the same non stop even if i try the tester!
Finaly the only way to stop it is to use the rewind button.

Also the counter sticks to number 4 frame, (and the shutter continius to photo with no stop)but this is not so important for me as the maim problem.

Do you think i have any hope with opening around shutter button or contacts,or to buy another ?

Thanks a lot

LOL... I have a MD-12 from a seller on this forum that does the same "shooting continuously" thing on a Nikon FE. I'm suspecting dirty switches. All of the switches tht need to be checked/cleaned/fixed require too much disassembly for the time/interest I currrently have available. One of these days I might take the motor drive apart but in the meantime they are inexpensive enough to just buy a replacement.

 

[Andreas Thaler]

Opening it is not that easy, but it is doable.

If you don't want to repair it, I'll gladly take it. Motor drives are my next focus

Please send me a PM in this case.

 

[coll]

Well i collect analogue cameras,old or more recent.
I decide to buy a set of nikon F3 (camera-lens,drive) but unfortunately i didn't give the needed attention to the seller feedback., and customer coments.
Thank God camera is ok

Τhank you Brian ,finaly i realised that all of them have more or less the same problems time brings.

Antrea i read also another old article from you about the disassembly of your MD4.
You mast be very good !!

My ΜD 4 is at very good external condition . Just only one paint scratch at the vertical part .Maybe a little dust at the frame counter, or to say the truth i need new glasses
I like to fix things but i realised also from your pictures that will be dificult enough the first try.
Fortunately I found around here another very good appearance one,for 50 euro.
I want to test it that days.
So !
I do not promise, but yes if i have a new one i can massage to you.
There is no professional service around here.

Thank you all again guys!
Have a good time