M-12 Motor Drive malfunction

I bought a M-12 Motor Drive on E-bay for $25.00, looked a little rough but

seller said it worked. Its got the Manual xeroxed but the problem exceeds the

manuals expertise. The first time I tried it it jammed up because the film was

not threaded properly, I think because it store the sprocket holes. The next

time I tried it, pressing the c or s button would not advance the film. I did

the coin test over the 4 contacts and the motor works properly then. When

mounted on the camera the light meter is activated in my Niko FE correctly, but

the film advance button will not work. When I put the manual film advance level

to open postion and the close it up to the camera body the motor drive is

activated and will advance the film one frame. One time after removing and

re-mounting the drive the film advance button did work for one or two frames and

then quit. It seems that the problem is an electrical contact with the film

advance button. The question is where to get it repaired and if the cost is

worth it considering the small amount I paid for the drive. One consideration

was that if the problem could not be with my FE instead?

Blaine,<br>

<br>

I had a problem with a Nikon FE2 and MD-12. I cleaned the

contacts with regent grade methyl alcohol. The MD-12 still failed

so I opened it up. I dont recommend this but Ive done

some lens repair on AIS Nikkors and thought this would be fairly

simple. I got information off the main circuit board and called a

camera repairman friend and asked if he would order me a part.

His reply was, Did you clean the contacts. I said,

Yes but Ill do it again.<br>

<br>

The second time around I burnished the contact with Q-Tip cotton

swabs very lightly moistened with methanol. I changed the Q-Tips

several times. Incidentally I cleaned both the camera and the

body both times as either side could cause the problem. The motor

drive worked perfectly after this and has ever since. There was

no viable sign of a contaminant on either set of contacts.<br>

<br>

My best guess is there was some kind of wax on the contacts.

Alcohols are not the best solvents of wax but they dry pretty

clean and are quite safe in this use. Regent grade methyl is the

solvent Nikon recommends for cleaning its professional

large format lenses which is why I have it on hand. Some care is

required of the raised contacts on the MD-12. The cameras

contacts are flat.<br>

<br>

I DO NOT recommend the use of ANY ABRASIVE including pencil

erasers. Im pretty sure pencil erasers use Pumice. If the

extremely thin gold plating is removed from the contact the brass

below will corrode, often in just a few days, and one will have

constant problems.<br>

<br>

Its doubtful that the problem is with your Nikon FE unless

its the FEs contacts. Make sure the MD-12 is turned

off when ever you install or remove it. I recommend that you

inspect the contacts on the MD-12 under magnification to see if

the plating is worn away. Those contacts may need replacement.

The MD-12 must have recently been discontinued as the Nikon FM3a

was recently discontinued. Parts should be available if needed.<br>

<br>

Good luck,<br>

<br>

Dave Hartman.

I tried cleaning the contacts with Isopropyl alcohol which is all that is available to me locally. However I think the problem is not with the contacts as the motor drive activates the camera light meter, the drive advances the film one frame if the camera is cocked and the film advance lever is pushed back to the camera. I also tried touching the contacts on the remote socket with a screwdriver and the motor drive advanced the film in continous mode. Attaching the remote cable and touching the two contacts had the same result. The only thing that malfunctions about 98 percent of the time is the button on top of the motor drive. The only thing that is does is activate the camera light meter.