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?