Repairing Seagull 4 Series Camera with Dual-lens Reflective Camera

The failure of the shutter blade is mainly due to the failure of the blade to open and close. To sum up, there are roughly three situations.

(1) Blade problem.

In the final assembly of each camera, some transmission parts are coated with a small amount of lubricating oil. After a period of use, the lubricating oil is constantly volatilized, and with the invasion of dust, the blade is easy to stick with an oil film. Sometimes due to the increase of adhesion, the main spring can't overcome this force, so the overlapping edge parts between blades stick together. Even if the shutter is tightened several times and the shutter button is pressed repeatedly, the blade can't be opened.

The elimination method is: use tweezers (or matchsticks), roll cotton, dip a small amount of gasoline, gently touch and wipe the adhesion of the blade, then close the shutter and press the shutter button, and repeat this several times, the blade will open; After the blade is opened, adjust the speed to 1 s, pull down the shutter wrench to make the blade in a semi-open and semi-closed state, and then wipe off the oil stains on the blade with clean cotton, and the fault will be eliminated.

② Problems of main spring or small hook spring.

The main spring is the "main force" to drive the shutter parts to operate. Whenever the shutter is tightened, it is in a state of tension, and after the shutter is released, it is in a state of relaxation. With such frequent use and repeated work, over time, the elasticity of the spring will gradually fall below the design requirements, and sometimes even break.

The small hook spring is installed under the small hook on one side of the main spring. When the shutter is tightened and loosened, due to the action of the small hook spring, the notch of the hook always hooks the blade ring pin (semi-cylinder), thus driving the blade to open and close repeatedly.

If the main spring or small hook spring has problems (such as fracture, deformation, looseness, etc.). ), the blade cannot be moved.

The maintenance method is: if the main spring is loose, you can tighten it with small pliers and continue to use it; If the small hook spring falls off, you can tidy it up with small tweezers and hang it up. If the spring is broken, you'd better find a thin steel wire of the same specification and tighten it yourself.

The maintenance process is as follows: first, close the shutter, take out the slow machine, remove the shift handle (the main spring and the small hook spring are both on the shift handle to avoid the spring jumping off during disassembly), and carry out maintenance according to the situation. After the repair, the main spring is clamped into the corresponding position according to its natural state; Then reverse it to the opposite direction of its stress point about 360 degrees, and at the same time, make the gap of unhooking catch the blade ring pin, so that the whole shift handle part is flat and firm; Finally, tighten the handle screw, install the slow machine and debug it several times.

③ The shutter release lever is deformed or the blade return spring falls off.

After the shutter release lever is deformed, the linkage ring under the lens base often cannot push it to the predetermined position, and the shutter mechanism is difficult to operate and the blade cannot be opened. When repairing, first observe the degree of deviation, and then correct it with small pliers according to the situation. If the return spring breaks, the blade will open and close when the shutter is tightened. At this time, according to the above method, take out the slow machine and repair the spring with tweezers. Shutter speed failure is mainly due to inaccurate speed. It usually happens at gate B, 1/8 seconds,115 seconds, 1/30 seconds. For example, gate B changes115 seconds, 1/8 seconds 1/60 seconds; 115 seconds becomes1second, 1/30 seconds becomes 1/4 seconds.

The above problems are mainly due to the deformation of some parts around the lens holder. In particular to a clamp, a clamp wheel, a sector wheel, a B door foot, a quick dial, a shutter release lever and other parts. So whenever the speed is not accurate, it is necessary to find the reasons in these parts and carry out maintenance.

(1) Gate B becomes115 seconds.

This is because the foot of door B is not in the A area (control groove) of the curve of the governor wheel, but is pressed by the governor wheel. During maintenance, just unscrew the pressure ring of the speed dial, remove the speed dial, lift the door B slightly with a suitable tool, then install the speed dial so that the foot of the door B is in the normal position in the curve area A, then put the shutter speed on the door B, press it evenly around the car body with your fingers and debug it several times.

② 1/8 seconds becomes 1/60 seconds.

This is because the convex part of the clamp seat deflects and deforms outward, thus entering the middle speed zone. In this case, you can take out the slow machine according to the above method, clamp the protruding part with small pliers, straighten it slowly (don't use too much force, or it will break easily) to make it perpendicular to the plane where the slow machine is located, then put it back in its original position and test it several times.

③ 115s becomes1sec.

This is caused by the deformation of the convex part of the clamp seat, but it deviates inward instead of outward, resulting in entering the low speed zone. When repairing, you can refer to the method of ②. After the bulge is corrected, the fault can be eliminated.

④ 1/30 seconds becomes 1/4 seconds.

This is because the loose speed dial makes the small round hole of the dial deviate from the locating bead, which directly affects the correct position of controlling the arc radius of the sector gear (because the arc radii of 1/30 seconds and 1/4 seconds are very close, this problem will occur if the speed dial is slightly deviated). During maintenance, as long as the governor is adjusted according to the original position, the fault can be eliminated. Generally, the airtightness of ordinary cameras is poor. After a period of use, the self-timer often fails due to the adhesion of oil dirt or the invasion of dust. Frequently asked questions are as follows:

(1) There is a phenomenon of "panting" when turning and stopping.

This phenomenon shows that more dust enters the self-timer and adheres to the meshing position between the gear shaft hole or gear teeth, which makes them unable to move flexibly.

When repairing, first loosen the tension spring of the selfie stick, unscrew the screws at both ends, take it out, immerse it in a small amount of gasoline, gently brush the oil stains on its surface and gear with a small soft brush several times, and finally clean it with cotton, dry it and put it back in its original place.

② Do not pull the self-timer wrench clockwise.

This problem is usually caused by the loosening of the fixing screws at both ends of the camera, which leads to the displacement of the camera, thus causing the wrench sector gear to be stuck by the camera control point on the lens base. If you pull hard, you will either break the wrench or damage the baffle, so you can't punch it.

The repair method is: just remove the tension spring of the selfie stick, slightly loosen the screws at both ends, push the position of the selfie stick up a little, so that the control stop is at the center outside the notch of the sector gear, then tighten the screws and hang the tension spring, and the fault is eliminated.

(3) The wrench passes and comes back.

There are three possibilities for this failure:

Firstly, the self-timer lever control reed inside the self-timer lever has been deformed, and it is impossible to control the temporary "braking" of the prime mover;

The second is that the sector teeth of the wrench are excessively worn and cannot mesh with the transmission gear;

The third is that the lobes or teeth of other gears are broken, thus losing control ability.

In case of the first of the above three faults, the selfie stick can be disassembled (be careful not to jump off the small spring when disassembling, and remember the original position of the spring and gear to avoid installation difficulties), and the control reed can be taken out for repair and can be used continuously; In the second and third cases, it is not easy for them to repair themselves, so they have to replace them with new parts. If there is nothing wrong with the flash itself, the flash will not flash after the power is fully applied, the synchronization line is connected and the shutter button is pressed, indicating that the flash linkage part of the camera has failed. This fault can be fixed on the three main parts of the camera.

The first part is the wiring on the camera, that is, the wiring between the universal flash socket and the lens holder. If one end of this connection falls off or breaks, the current cannot pass. The position of the connecting wire is inside the mask, which can be seen by removing the mask. If it is broken, you can weld or tighten the screws according to the situation.

The second part is the tripod metal plate linked by the flash on the camera. The metal sheet is under the governor wheel, near the foot of door B, which is the flash contact point. If the tripod metal plate or the spring hanging on it is loose, the metal plate can't hit the fuselage, so it can't form a "short circuit" and the flash won't flash. Maintenance, just take off the mask, take off the speed dial, and install the tripod metal plate or spring, and the fault can be eliminated.

The third part is the center point of the flash socket on the camera and any metal part of the fuselage. This is a way to check this part when no fault is found in the above two places. It depends on the electrical blocking test circuit of the multimeter. The test steps are as follows: first, put the shutter on the B door, press the shutter button, put one electric pen (positive or negative) of the multimeter in the center of the flash socket, and the other electric pen touches the metal part of the camera. If the pointer on the meter does not move, it means that the camera is not connected, and then use two electric pens to test the connection line and synchronization line respectively until something goes wrong. When the camera is in use, it often comes loose unconsciously because of wiping the lens with suede and absorbent cotton. If it is loose outward, the focal length will inevitably become longer, which is inconsistent with the focal length of the lower lens. Therefore, although the focus is at infinity, the scenery at infinity is not clear, and it seems that it is necessary to turn around infinity to be clear. If it reaches Marie Laure Gigon, the focal length will be shortened, which is also inconsistent with the focal length of the lower lens. So when you focus on 10 m and 20 m, the scenery at infinity is not clear. It can be seen that if the above failure occurs in the upper lens, there will be a focus error, and it is difficult to obtain a clear picture.

The steps and methods to eliminate this fault are: take off the hood, rotate the focus button to the scale of 1 m, loosen the small screw at the top of the lens with a small screwdriver, then turn the focus button back to infinity, open the viewfinder, and observe the scene clarity at infinity on the ground glass while rotating the lens. Debug it back and forth several times until the scenery at infinity is completely clear, and then tighten the small screw to eliminate the fault. The looseness of the lower lens, like the upper lens, does not meet the camera's requirements for lens focal length design. However, the problem of loose lower lens is not reflected in the ground glass, but directly reflected in the imaging position of the film. Therefore, when shooting with this camera, the negative image must be blurred when the focal length of the upper lens is normal.

The repair method of the lower lens is as follows: open the back cover of the camera, use a piece of ground glass (or a piece of translucent paper) with appropriate size to cling to the negative window, turn the focus button to infinity, fully open the aperture, and put the speed on the door B to make the shutter blade open for a long time. Then, rotate the lower lens repeatedly according to the above method. When the infinite scenery displayed on the ground glass (or translucent paper) is very clear, the fault is eliminated. If the focus of the upper and lower lenses is not accurate, it will cause confusion in focus and shadow, so it must be repaired in time.

If it is not accurate to the same extent, it can be adjusted separately according to the above method; If they are not accurate to the same degree, that is, by observing on the frosted glass and negative window of the frame, the scenery at infinity or at the same distance is clear, but the photos taken are blurred, which indicates that the fault is not in the two lenses. Because the focal lengths of the two lenses of this reflective camera are the same, and they all move in parallel at the same time and distance, the scene images reflected on the ground glass and the focal plane should be the same. However, with the above problems, the result is just the opposite. The reason is that the internal mechanism of the focus button has failed, causing the focal lengths of the two lenses to change together.

Maintenance methods of Seagull 4 and 4A cameras;

Step 1: Unscrew the serrated glass pressure ring on the cross section of the focus button counterclockwise, and take out the transparent plexiglass, glass washer, object distance dial, depth card and depth washer in turn. At this time, you can see the focus shaft nut, focus spindle, push-pull ring, focus wrench and so on. The problem lies in these places.

Step 2: Open the view frame, aim the lens at the scene at infinity, then turn the focus knob to observe the change of the scene on the ground glass, and pay attention to the best point at infinity on the knob. Find the best point, press and hold the focus knob by hand, loosen the focus nut, so that the inclined plane of the push ring is loosened from the focus knob, and then use the focus knob to drive the focus wrench to rotate to infinity until it can't move, and the focus is adjusted. Finally, tighten the focusing shaft nut and install various accessories in turn.

Maintenance methods of Seagull 4B and 4C cameras;

These two kinds of cameras. Compared with Model 4 and Model 4A cameras, the principle of focusing part is exactly the same, but the shape and installation method of some parts are different.

The repair sequence is as follows: firstly, remove the artificial leather from the circular surface of the focusing knob, remove the small aluminum cover, unscrew the two hexagon nuts on the focusing shaft and take them to the focusing knob. Then, open the view frame, aim the lens at the scene at infinity, rotate the focusing spindle, and observe the changes of the scene on the ground glass at the same time. After the scene is completely clear, install the focus knob on the shaft so that the symbol (∞) at infinity on the knob is aligned with the value of 3.5 on the depth of field table. Finally, put the washer, tighten the hexagon nut, stick the artificial leather cover, and the focal length will be adjusted. Seagull 4 camera with automatic film stop device. Under normal circumstances, each film will automatically stop. There are many reasons why you can't stop the film automatically, but the most common ones are three:

The first reason is that the differential spring between the stop gear and the twelve-grooved wheel falls off or breaks;

The second reason is that the spring under the winding plug has fallen off or broken;

The third reason is that other transmission gears are deformed.

In the first case, the twelve-grooved wheel is difficult to rotate because it loses the tension of the differential spring, so the winding plug always leans on the tooth surface between the notches, and the other end of the plug always comes out of the teeth of the handwheel, so the winding button has no mechanical resistance and it is impossible to stop the film automatically. When repairing, unscrew the central screw of the stop wheel, take out the stop wheel and twelve-grooved wheel, hang the differential spring between them, and then install it in the original position.

In the second case, because the spring under the winding plug is exposed, its specific fault can be known at a glance, and it is easier to maintain.

If it does not belong to the above two situations, it must be carefully checked on other transmission gears and other parts, such as whether the teeth are worn or not, and whether the parts are deformed. This kind of fault often happens on Seagull 4 camera. The reason is also caused by the failure of twelve-grooved wheel, winding head and winding driving wheel. Therefore, in this case, you can first refer to the above method for repair. If no fault signs such as spring cracking and gear locking are found, you can check whether the winding plug is deformed. Because after the film winding head is deformed, it is possible to make its pawl (the tip part is called "pawl") tightly abut against the teeth of the film winding handwheel, thus affecting the film winding. If this is the problem, just loosen the plug spring, unscrew the screw, take it out and clamp the neck of the tip with small pliers, pull it slightly in the opposite direction of the tip, and then install it in the original position. After several debugging, the fault can be eliminated.

If the seagull 4A camera can't roll up the film, its repair principle is similar to that of the seagull 4 camera. As for the cameras of Seagulls 4B and 4C, since there is no automatic stop device, this kind of fault generally does not occur. This refers to the problem that when the focus button rotates, the focus button itself is like a wheel slipping, which can't drive the guide frame and the lens to do telescopic movement. If the lens can't be telescopic, shooting can't be done. This kind of fault, except that the main shaft inside the camera is broken, is usually that the nut on the focusing shaft is loose. After the nut is loosened, the focus shaft can't drive the cam, the guide frame and the lens to expand and contract, and the focus button can't move.

Please refer to "7" for repair method. Remove all parts in the focus button, check and adjust the focus, and then tighten the loose nut. There is a circular depth of field card in the focus button of Seagull 4 and 4A cameras. It mainly relies on its own three small feet hooks and a small amount of adhesive on the washer. Due to the frequent rotation of the focus button, this depth of field card is easily affected by friction and often becomes loose and dislocated. After the depth of field card is shifted, its arrow will deviate from the correct position, which will not hinder normal shooting, but it will bring some trouble to accurate ranging and depth of field calculation, and should be repaired in time.

The repair method is simple: just take out the depth of field card according to the steps mentioned in "7", remove the residual dry glue on the back of the card body, gently clamp the three small hooks with small pliers, re-coat the glue, turn the focus key to infinity, stick and hook it in the direction of the arrow, and then install other components in turn, until the glue is dry.