一、滑动框自行下滑．产生此故障的原因是滑动框与燕尾拖板间隙较大．格修时，先取下滑动框，旋松斜导条上的四只螺钉，将斜导条向内靠紧，初步因紧四只螺钉，使用动框与燕尾板紧密滑配，然后旋紧四只螺钉．二、底片中有黑色块状现象．出现此现象的原因；（1）推进箱上的皮腔有 First, slide the box on its own decline. The reason for this failure is the large clearance between the slide frame and the dovetail carriage. Lathe repair, remove the sliding frame, loosen the four screws on the oblique bar, the oblique bar inward by tight, initially due to the tight four screws, the use of movable frame and slide swallowtail closely with the slide, and then tighten the four Only screw. Second, the film has a black block phenomenon. The reasons for this phenomenon; (1) promote the skin on the box there