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Polaroid SX-70 User's Manual

1. c Close S6 and S7 and apply power 1 If the camera cycles the motor and MCC are OK and the shutter is defective 2 If the camera fails to cycle check the motor and MCC by continuing below d With the 1000 ohm resistor still in place connect a jumper wire between the motor minus TP9 contact and the battery minus TP1 contact for a moment 1 If the motor runs the MMC is defective 2 If the motor does not run the motor is defective e Remove the jumper immediatly after determining the fault aera 2 Camera Analysis Charts Once familiarity with the system is gained repair people can rely on the failure analysis charts to troubleshoot camera problems When the charts lead you to a repair procedure refer to Section IV Repairs and Adjustments for the necessary information Set up the test equipment as shown in Figure 3 18 The film pack simulator is inserted into the camera and the negative lead from the VOM is connected to camera ground through the power supply This allows all the tests to be completed simply by moving the VOM lead as a probe from point to point Figure 3 19 will assist you in locating the test points or terminals called out Sa oeter renge for minimum of 6 6 vE Figure 3 18 Testing instrument connections X 70 SHUTTER TEST POINTS To be used in conjunction with Faliure Anatysis Tree OL 1 Figure 3 19 Test points on SX 70 shutters L al oa 4 Pre T i ei i
2. DESCRIPTION A GENERAL DESCRIPTION The Polaroid Land SX 70 is a folding pocket sized single lens reflex camera which takes and immediately delivers full color pictures approximately 31 4 inches square see figures 1 1 1 2 and 1 3 Operation is automatic the user merely inserts the film focuses and shoots power is provided by a six volt battery inside the film pack therefore the batteries are always fresh as the film The four element lens has a maximum aperture of f 8 and a focusing rang from 10 4 inches to infinity The shutter is automatically controlled by a photocell and electronic timing Electrical to mechanical energy conversion is accomplished by two solenoids and a motor There are no separate diaphragm adjustement The shutter opening and closing time is controlled by the exposure measuring system Figure 1 1 SX 0 Camera folded Figure 1 2 Holding and opening the SX 70 VIEWFINDER SHORT COYER FOCUSING KO SHUTTER RELEASE 51 FRONT COVER SHUTTER Figure 1 3 Opened for picture taking The subject is viewed and focused throught the taking lens a mirror a Fresnel viewing screen with spilt image focusing aid and a optical system to focus the image at the viewing eye piece As in all single lens reflex cameras the shutter must be open to provide an image at the eye piece This requirement is fulfilled by the automatic electro mechanical components which are described in
3. 4 A r t iy wji PEE aii SS ee ee ee m i pee i hy 4 F i i i mL l T i i wey Eel a il LA i 1 4 4 i 5 IV REPAIR AND ADJUSTMENTS INTRODUCTION This section of the manual is primarily devoted to disassembly reassembly procedures These procedures provide step by step instructions aimed at guiding the technician through the intricacies of SX 70 camera repair The procedures cover such things as replacement of improper linkages or connections repair of electrical malfunctions and adjustments needed to return the camera to proper operation It should be stressed that these procedures are intented to serve as guides for the experienced repair technician Except where noted otherwise the actual repair procedure to be used is left to the discretion of trained personnel Their combination of training and experience should be sufficient to allow repair personnel to make on the spot judgements a to the best method of repair A major factor which must be considered is the trade off between time and cost materials If the repair is easy and feasible from a cost viewpoint it should be made Otherwise replacement of a part or sub assembly is the proper choice There is one other general note that pertains to SX 0 camera repair Occasionally screw holes in the plastic become stripped This is most apt to occur in the counter mouints the motor mounts and where the rear upper inn
4. 1 Exit Pupil Test a Mount the exit pupil gage onto the camera eye lens Figure 3 12 1 Engage the left side gage rail on the eye lens The right side is identified by a 3 4 horizontal slot 2 Slowly slide the right side in place A distinct Figure 3 12 Installing the exit pupil gage Figure 3 13 Aligning the exit pupil gage 3 The mounting rails for the gage must be flush with the eyelens frame Check by holding the bottom of the eyelens frame with the thumb and apply slight pressure in the upper front of the gage with the right index finger The gage should be secure NOTE Aleft handed person may find it easier to rerverse the mounting and securing process b Point the camera lens at a light source while holding the viewfinder eyelens with gage about18 inches away from your eye c Align the bottom of the viewfinder cap with the horizontal white line on the front of the gage Center the eyelens supports with the vertical VERTICAL MISALIGNMENT A HORIZONTAL MISALIGNMENT C Figure 3 14 Exit pupil images lines Figure 3 13 d Close one eye and view the exit pupil image in the gage e To be within acceptable limits the pupil a bright circular image must appear in the center of the square opening in the face of the gage If the pupil is not in the center adjust the optics system according to instructions in Section IV Viewfinder Sytem 2 Entrance Pupil Test a Set t
5. No flash fire signal if A a S9 closed empty pack b new pack inserted with array already inserted S8 function Note 2 A 25 to 34 exposure results if the array does not fire Removes power from flash circuit S4 BC 20 pick starts 45 spread starts 50 pick stops and latches 130 mirror starts to recock S3 260 spread stops 325 mirror is recocked pick returns S5 345 lll TROUBLESHOOTING A INTRODUCTION The Sx 70 camera is an electronically controlled device the electronics being in the integrated circuits IC mounted in the Electronic Control Modul ECM and Flash Fire Assembly FFA in the shutter housing and in the Motor Control Circuit MCC in the camera back Because the IC s are non reparaible items there is no requirement to trace faults whithin the integrated circuits It is mandatory however to be able to identify the command inputs switches open or closed etc and the resulting output signals The SX Ocomprehensive Tester provides the readouts necessary to confirm an exposure malfunction but thorough understanding of the theory of operation is required if meaningful use of the tester is expected If a particular camera function fails it is necessary to recognize how the failure is related to the operating sequence of events and thus reduce testing procedures to those related to the aera malfunction Because of the camera s total automation it is unlikely that much
6. configuration shutters the flash will fire whether or not sufficient ambient light si available At the end of the flash delay the blades at this point are open to the aperture dictated by focusing power is removed from solenoid 2 and the discharge flyback voltage triggers the flash circuit firing the flash and starting the flash time out interval the fixed exposure time If on early cameras an ambient exposure has been made S T 2 in the ECM receives the signal and no flash or flash time out occurs At the end of the flash time out the circuitry energizes solenoid 1 which closes the blades if no flash has occured caused by all the bulbs having been used no signal will be sent to solenoid 1 and on early cameras an ambient exposure will be made If the S T has not collected sufficient light energy at the end of a fixed period 20 seconds the blades will automatically close On newer cameras the exposure time remains short and a black picture will result AMBIENT S1 S4 BC S5 S3 End ny t S4 AC 20 to 35 ms Integration lt _ _ ST 2 S4 BC S3 S5 EXPOSURE PROCESS OPERATION SEQUENCE e S9 opens when previous pack removed e S6 closed during the erecting mode e S8 closed until film cover ejected e Gears between front cover and gear train mesh as cover closes 3 4 amp 4th idler e S7 closes during front cover closure resulting in dark slide ejection a
7. ECM removes the power from solenoid 2 The solenoid like any inductive device produces a flyback voltage when its magnetic field collapses This flyback voltage is used to trigger the ECM which in turn applies power to the FFA to ignite the next unused flashbulb o The shutter performs an additional function in the flash mode One of its circuits examines the 1 flashbulb contacts and by virtue of the resistance determines whethever or not the bulb has been fired If the 1 lamp is exhausted the circuit scans the 2 etc When an unused lamp is located the firing circuit remains connected to the lamp until is used NOTE It is important to be aware that in early cameras the timing integration circuits of the substrate continue to function even though the insertion of a flash array has placed the substrate in the flash mode Thus if the ambient light level is high the picture may be made by ambient light without firing the flash Also if all the flash lamps are expended and a picture is taken an ambient light exposure will result The photographer will recognize this situtation by the absence of a flash However he may still get an acceptable picture the aperture in this case will be determined by the flash to subject distance FLASH TIMING SEQUENCE CHART End Sol 1 S3 Sat Power Opens Down Sol 2 Activated Sol 2 Down Sol 1 SA BC Power Flash delay Power Off S4 BC S3 Power Up Closes Down FD FF Closes Close S5 Bl
8. all power will be removed and the shutter blades will open to permit viewing If the button has not been released the shutter blades will remain closed until the operator removes his finger from the button l When a flash bar is placed in its socket it closes switch S2 This switch connects the ECM in the flash mode All of the mechanical sequences will remain as just described The ECM however will now provide power to solenoid 2 when switch S5 in the gear train opens and will maintain it in a power down condition when S3 opens m Within the shutter assembly a cam follower is driven by a cam on the focus wheel and arranged so that it will mechanically stop the travel of the shutter blades relative to the focus distance When solenoid 2 is not energized a spring on the cam follower prevents engagement of the cam follower and the shutter mechanism functions in the ambient exposure mode When the ECM is programmed for flash solenoid 2 is energized and the shutter openeing is controlled by focusing distance n When making a flash exposure and the shutter blades start to open the interceptor will be set to a position determined by the focusing mechanism but out of the path of the interceptor pin When solenoid 2 is energized it pulls the interceptor into the pins path of the blades and stops them at the aperture for flash exposure at the set distance Figure 1 13 The interceptor latches in this position At this time the
9. blades may not be permittedto open completely because of the follow focus mechanism described in part in the foregoing paragraph The following paragraph explains the interaction of the follow focus components and the shutter blades 4 Installing a flash bar in the camera flash socket switches the ECM to the flash mode As previously explained at a point in picture taking sequence flash mode solenoid 2 is energized Fastened to the plunger is pull down bar when the plunger pulls this bar down it moves the interceptor into the position where it will intercept a pin the stop pin on the walking beam Figure 2 9 A Now when the shutter blades move towards the open position they willbe interrupted by the mechanism just described which means the maximum size of the blade opening aperture is determined by the focus setting of the camera As the camera and thus the flash lamp is moved closer to the subject the maximum aperture is reduced so that a correct exposure will result The reverse greater distance greater aperture is also true eS SoLUENDIN Sil ji N lt i r Fe P t ker INTERCEPTOR wah Cnt STOP FIN WALKING HE AMM Figure 2 9A Solenoid S2 operation 5 The shape of the pin on the walking beam si such that once contacted by the cam interceptor it remains latched in that position until solenoid 1 actuated during the next phase of the shutter cycle When the plunger
10. center target top group of lines and note the number 63 This number and the lines should have maximum clarity as the focusing wheel reaches infinity 5 if the wheel stops before the focus is sharp make the following adjustment before continuing with the collimation procedure Spring Loaded Idler Gears a With the camera still on the colimator slip special tool 11939 over the lens and push it in toward the back of the camera This will disengage the idler gear from the focus wheel allowing the lens to be turned without affecting the focus wheel b With the focus wheel still set it its infinity position look through the camera while turing the lens This is done by maintaining pressure on the tool While turning it you will be able to see the target through the opening in the tool c When the image is sharpest release the special tool to reengage the refocused lens to the focus wheel Continue setp 6 Non Spring Loaded Idler Gears a Remove the camerar from the collimator b Loosen the adjusting screw at the bottom of the shutter housing so the idler gear no longer engages the focus wheel and lens barrel Figure 3 5 c Return the camera to the collimator and adjust the infinity focus by rotating the lens barrel while maintaining the infinity position on the focus wheel d When the focus is sharpest remove the camera from the collimator and tighten the adjustement screw Returns the camera to th
11. during the actual exposure As soon as the exposure is complete the mechanism returns the viewing screen to its initial position and the picks feeds the exposed film to the spreader rolls The rolls break the pod spread the developer and eject the film from the camera 7 Completing the film pack As each exposure is completed the exposure counter substracts one digit until the 10 exposures have be made The counter then indicates 0 When this occurs switch S9 is closed Closing this switch inhibits the flash and the exposure timing Since the counting cycle is initiated by the insertion of a film pack the pack may not necessary contain a full supply of film If for some reason a partially used pack is removed and reinserted the top film will be the dark slide The counter will start at number 10 Since switches S8 and S9 are physically attached to the counter the camera will cycle through 10 exposures even though there be less than 10 sheets of film in the pack This deviation must be recognized whenever a partially exposed pack is used 8 Developing the print As in orther Polaroid pack cameras the picture is developed ouside the camera Unlike previous Polaroid Land Cameras however there is no negative to pell off and discard 9 Exposures using flash The SX 70 accepts a special 10 lamp flash bar that plugs into a receptacle directly over the camera lens There are five lamps in a rowon either side of the bar wh
12. film and as the sheet is passed between rollers the pod is burst and the chemical spread evenly between the negative and the mylar protective cover Except for this characteristics no direct similarities exist The SX 70 camera employs a unique process which totally eliminates the throw array negative The print is drawn through the spread rolls by the motor drive system so that no action need be taken by the operator See Figure2 10 Development takes place outside of the camera and unaffected by ambient light conditions Since the end result is determined when the picture emerges from the camera no time measurement si necessary Additional film information is available on page 60 and 61 of The world of SX 70 Figure 2 10 Spread roller system H SEQUENCE OF OPERATIONS The operator pushes S1 applying full power to solenoid 1 which closes the shutter blades and pushed solenoid 1 against S4 changing it from CA to CB Closing CB cuts solenoid 1 s power from high to low low is enough to hold the blades closed Closing CB also signals the ECM to start the motor The motor starts the gear train moving The movement of a cam on cam on the gear train releases the recock ram and through spring action raises the Fresnel carrier When the recock rammoves it opens S5 and then S3 at certain Fresnel carrier angles Opening S5 stops the motor after it has made only a brief jog Opening S3 starts the Y delay 40 milli
13. flex circuit insert a thin strip a small metal six inch pocket scale for example between flex circuit and the inside cover surface Move the tool from one locating stud to the other as the cover is being removed to prevent sticking to the flex circuit 6 Lift the cover a small distance away from the camera then slide the cover from the assembly 7 remove the _ inner frame to boot retainer screws Figure 4 8 RETAINING SCREWS Mew cam ras have no center screw Figure 4 8 Boot retaining screws Figure 4 9 Shutter mount retaining screws RETAIMING SCREWS LEFT SIDE 8 Remove the four shutter housing retaining screws from the rear of the shutter mounting hinge bracket Figure 4 9 Check for square head or Bristol head screw Replace with same type Caution While the shutter is detached from the mounting bracket make sure no mechanical stress is put on the ribbon cable 9 Remove the two hinge bracket to boot retainer screws located adjacent to the round lens opening in the shutter hinge bracket Newer cameras have rivets which must be removed RET APNG o SCAEWS L RIGHT SIDE VIEW B
14. is energized it engages a mechanical coupling between the shutter blades and the focusing mechanism ike as LN eae jee c Switch S3 normally closed at the begining of the exposure cycle is opened by the recock ram located in the gear train assembly See Figure 2 7 As the exposure sequence begins S3 opens and actuates a delay circuit Y delay in the EMC which retards the start of the actual exposure approximately 40 milliseconds so that mirror bounce will have subsided before a picture is taken At the end of the delay time the shutter starts to open and the electronic timing function integration takes place If a flash circuit is inserted into the FFA S2 closed an additional flash delay circuit is avtivated to insure that the exposure gets full effect of the light derived from the flash At the end of the exposure cycle when the Fresnel carrier moves down into viewing position S3 closes as the recock ram moves away It is now reset for the next camera cycle d Switch S4 is tripped by an actuator on the plunger of solenoid 1 the shutter blade actuating solenoid Figure 2 8 RECOCK ARAM 65 CONTACT Figure 2 7 S3 Being opened by recock ram NOTE Wheneverthe SX 70 shutteris discussed it must be noted that since the camera is a single lens reflex and focusing is accomplished through the taking lens the shutter s normal state si open not closed as in other Polaroid cameras When the shutter release button
15. of the fixed viewing A first surfaced taking mirror is fastened to mirror Figure 1 8 B the underside of the Fresnel carrier assembly The image is reflected by the mirror onto the film surface the electronic metering system determinesthe required exposure and programs the shutter opening and duration accordingly The incorporation of a mirror in tghe lens to film path necessitated by the nature of the film No separate negative film is employed Instead the image appears as a direct positive Since the final product is an opaque print it is viewed by reflection As a result the mirror is needed to reverse the image so that the final print will be properly oriented This requirement in turn dictates the use of the reflectance type viewing screen rather than a ground glass type transmission system Note that the film surface is deplaced from the Fresnel viewing screen by the thickness of the viewing screen assembly The correct focal distance for both viewing and exposure is properly maintened however since the surface coated exposure mirror is deplaced by the same dimension During exposure the light from the viewing system must be prevented from striking the film This is accomplished by a rubber light stop adhered to the hinged Fresnel carrier When the Fresnel carrier moves upward the light stop blocks off light from the viewfinder eyepiece As indicated by the foregoing description the viewing system is blacked out
16. the viewing position S5 is closed by the recock ram and stops the camera cycle SOLENOIO Fi f Switch S6 is closed by openong the camera to the picture taking position Its disconnects the negative side of the battery from the commun return ground when the camera is folded to assure the removal of power from the circuit g Switch S7 is closed when the front cover is closed It is wired in series with S6 Like S6 S7 disconnects the negative side of the battery from the commun return so that the camera cannot function until the front cover is closed and latched It is an interlock during normal picture taking With S6 and S8 closed it initiates the dark slide function h Switch S8 Figure 2 8 A is part of the exposure counter operated by the counter wheel As S7 closes power is applied ejecting the dark slide After the dark slide ejection the counter wheel turns opening S8 S8 then remains open until the film pack is removed When the pack is taken out S8 closes i Switch S9 is near S8 on the exposure counter assembly When the counter reaches the O position switch S9 closes and the ECM inhibits the falsh firing function so that if an unused bulb is still available it will not be wasted j Foran handy summary see the Switch Function Table 3 Function Sequence The following paragraphs describe the sequence in which operate during normal operation of the camera a The operator opens the camera Switch S6 co
17. to 6 25 cdls ft In this case the filters are labeled so that the proper label 100 or 6 25 must facing the operator when the filters are used Caution To avoid possible delamination of the filters do not leave the Comparalumen on at 100 cdls ft any longer than necessary It should not be on any longer than the minute or two needed to check the camera POWER SUPPLY FIXTURE Figure 3 8 Light leak test system camera in the mirror up picture taking position Both of these tests must be done in a darkened aera a Static tests 1 Erect the camera and remove the front cover assembly Close S7 2 Turn on the power supply and insert the light leak fixture into the camera film compartment The camera should run through the dark slide eject cycle 3 Darken room 4 Press and hold the fixture trigger 5 Examine the camera from all angles looking for light leaks Note the location of any light leaks and continue below with the dynamic test Leak are most likely at the hinge aera between the inner frame and mirror cover and at the boot tab aera b Dynamic tests 1 Cover the photocell lens and trip the shutter With the photocell lens coveredn the mirror should stay in the raised picture taking position long enough to perform the dynamic light leak test approximately 13 28 seconds 2 Press and hold the fixture trigger 3 Examine the camera for light leaks Gently flex the boot while looking f
18. useful guidance can be obtained from customer complaints except in cases of visible mechanical damage For this reason a well defined series of checks observations and tests must be followed This section of the manual defines these procedures The primary purpose of any fault analysis program is to reduce the investigation time to a minimum Thus it is not only important to establish a fixed routine but it is mandatory to acquire the maximum amount of information from each step of the checkout procedure Use the charts at the end of this section to guide through each step of inspection dynamic testing and post repairs tests Analysis of the SX 70 camera is a key part of the complete repair task If the analysis is done correctly it will eliminate excessive repair time and high parts replacement cost For instance initial evaluation may show the entire shutter to be at fault however continuing analysis determines that the problem is in solenoid 2 which when replaced reduces the materiel cost considerably from over 20 to under 2 The repair person must always consider the labor vs material trade off when making a repair B INITIAL TESTS Do not make any arbitrary assumptions An assembly or component should be thoroughly tested to determine whether or not itis performing its function correctly Complete the tests in the chart below SX 70 CMAERA REPAIR INSPECTION PROCEDURE A FUNCTIONAL TEST 1 Perform light le
19. wheel and rotate the wheel to the 10 4 setting 15 Set the flash mode aperture switch to 10 4 16 With the photocell still blocked press the exposure button and observe the APERTURE meter 17 Record the 10 4 APERTURE reading and compare it to the STANDARD Chart 18 If the reading is high at the 8 foot setting and the needle goes off scale at the 10 4 setting the interceptor mechanism is defective See Section IV for repair adjustment 19 If on scale readings are obtained for 8 but the 10 4 reading is either high or low the interceptor can be adjusted The problem can be either the interceptor link or the interceptor cam See Section IV for repair adjustment 20 When repairs adjustements interceptor on Wrong Side of Stop Pin MODEL B CAMERA TESTER a Set up 1 Be certain that the comparalumen light source and electronics module are on a flat work surface and plugged into separate 110 VAC outlets 2 Plug the cable assembly from the horn into the socket located on the front of the electronics module NOTE There is no warm up time required for the Model B Tester components b Comparalumen Light Specifications The following table shows the luminance levels of various setting used for camera testing c Ambeint Exposure Measurements 1 Remove the front cover from the camera 2 Close the S7 switch using the S7 actuator 3 Set the L D control to the mid range pos
20. 0 Figure 1 7 indicating that 10 pictures remain in the pack Figure 1 7 Counter 5 Viewing and focusing Viewing and focusing is accomplished through a reflect system Figure 1 8 A In the viewing mode the image passes through the lens to a fixed mirror which reflects it down to the Fresnel viewing screen The viewing path from the viewfinder eyepiece lens is from a parabolic mirror and wafer lens off the fixed mirror to the Fresnel screen On most cameras the Fresnel screen contains a circular split image aera which is used to focusing aid A knurled knob the focusing wheel on the shutter housing is rotated to adjust the camera focus The scene is in focus when a vertical line within the split image aera is perfectly straight On early cameras without a split image feature the scene is in focus when the image seen on the Fresnel screen is sharpest 6 Viewing and focusing The exposure is made by pressing the release button This completes the electrical circuit to the CONCAVE EYEPIECE LENS PARABOLIC WAAGA WAFER LENS TER Vik Wing MINOR FRESNEL SCREEN SHUTTER OPEN VIEWING MODE FRESNEL SCREEN FILM BEING EXPOSED E POSURE MODE Figure 1 8 Viewing and shooting shutter to initiate a series of events The shutter The shutter opens and closes to perform the blades close to cut off the optical path The exposure function hinged Fresnel viewing screen is swung upward and comes to rest in front
21. ECTRONICS MODULE MOUNTING HORN Figure 3 7 Model B Camera tester b Ambient mode exposure test 1 Place the S2 switch int he OPEN position Set the voltage to 5 8 volts 2 Set the light level selector to the desired 100 light level 3 Slide the camera over the horn on the tester The camera should go through the dark slide S8 cycle If not remove the camera from the horn determine the cause of failure and correct the dark slide operation If the camera cycles correctly push the simulator flash plug all the way down into the flash socket 4 Read the current meter it should read 0 after the dark slide cycle 5 Press the exposure button and hold it down while observing the exposure meter The readings must compare to the specifications shown in the Standards paragraph at the end of this section When the exposure is released the meters will automatically reset 6 Observe teh BATTERY DRAIN meter The reading should be according to specifications This test applies only to the first exposure of series 7 Release the exposure button actuator All of the meters will reset automatically 8 Repeat steps 5 through 7 twice a total of three times The exposure readings observeted must be within specifications 9 Move the light level selector to 6 25 Repeat steps 5 through 7 The reading must agree with specifications 10 Move the light level selector to 800 Repeat steps 5 through 7 All
22. OR CODE ON CAMERA Gears in the front cover must engage the main gear train of the camera before the gear train is put into motion A switch S7 located in the forward section of the gear train compartment initiates the application of power to the gear train drive motor Switch S7 is actuated by two components 1 A projection on the front cover latch Figure 1 6 A and 2 A poston the right rear edge of the front cover Figure 1 6 B A FRAOJECTION 7 CONTACTS OFEN 57 ACTUATOR POST 37 CLOSED Figure 1 6 S7 contacts open and closed Thus the cover must be fulled closed the gears engaged and the latch fully seated in order to actuate the drive motor As S7 closes power is applied to the drive motor S8 is also involved and is discussed in a following paragraph the gear train is set in motion and actuates a device called the film pick The pick engages the dark slide pushes it into the spread rolls and the dark slide is ejected from the lower front edge of the front cover The camera is now ready to take the first picture 4 Setting the exposure counter When a used film pack is removed from the film chamber the action automatically resets the exposure counter at the rear of the camera to the start position closing S8 With a new film pack installed and the front cover closed and latched S7 closed the motor is powered and the dark slide is ejected The exposure counter turns to number 1
23. Open S1 Blades close motor brakes no reaction Open 3 Blades open then close fixed time no flash motor runs Close 3 Blades close motor runs Close S5 Blades open motor brakes a eR We Pa a i aOR WAR a 34 EYE LENS aan H K corn wf i he iy CONCAVE lt i a MAROR w S amp as FRESNEL TAKING SON TAKING MIRROR l MIRROR Ds LENS i iy A eea 4 ie 5 e _ i I F n ae TE pre Pe TT ee a cor ae ee Figure 3 11 SxX 70 Viewfinder system D OPTICAL SYSTEM Viewfinder quality refers to the general qualityand clicking will be heard when the gage is alignment of the camera optics For the user it secure can be precisely defined as the appearance and clarity of the image as seen through the viewing system Figure 3 11 When a camera has poor viewfinder quality it is difficult to obtain a sharp image Certain parts of the field always seem out of focus and the image lacks crispness having a hazy appearance usually in the vertical plane Since flash pictures are critically dependent on accurate focusing a poor viewfinder system will make the taking of good flash pictures difficult Failure Analysis Chart 5 will enable you to trace most problems in the viewing system to their source Corrective actions are shown and where they are complicated are presented in Section IV Presented here are several checks with require greater detail than the charts provide
24. URE MODE switch to the center RESET position NOTE If ameter reading goes off scale greater than 1 stop press the 1 stop pushbutton on the electronics module and read the meter adding 1 stops to whatever the meter is indicating 4 Light Leak Tester Figure 3 8 Caution When using the light leak tester always hold the fixture so the camera is in the uppermost position witgh the lens pointing down There is no latching device on the fixture and the camera could slide off it the fixture were pointed down The light leak tester consists of two checks the static test with the camera in the mirror down or viewing position and the dynamic test with the COMPARALUMEN LIGHT LEVELS TABLE 800 cdls ft Move the center switch on the Comparalumen to the right to illuminate the right high level screen No filters are used for the 800 cdls ft level Proceed as for the 800 cdls ft level but insert both filters one stop down and two stops down into the slot above the right high level screen Move the center switch to the left to illuminate the left low level screen No filters are used for the 50 cdls ft level Proceed as for the 50 cdls ft level but insert both filters one stop down and two stops down into the slot above the right low level screen 100 cdls ft 50 cdls ft 6 25 cdls ft NOTE On some Comparalumens it has been found necessary to reverse the filters when used to reduce the 50 cdls ft
25. URE meter is used in this test It is calibrated in stops and when the test is performed it will indicate stops deviation from the ideal design aperture To perform the follow focus test proceed as follows 1 Set the camera focus to infinity and the L D control to mid range Set the power supply to 5 8 volts 2 Remove the front cover from the camera and install the S7 switch actuator 3 Install the camera on the horn of the tester The camera should go through its dark slide cycle 4 Remove the camera from the tester and set it on the collimator 5 Swing the 8 and infinity lenses into their vertical positions on the collimator and look through the camera 6 Turn the focus wheel unti the vertical line in the center target is straight refer to Figure 3 4 The camera is now collimated for the 8 setting Tape the focus wheel so it can t be accidently moved 7 Remove the camera from the collimator and place it on the tester 8 Install the flash simulator plug into the socket on the camera and close the S2 CLOSE OPEN SWITCH 9 Set the light level selector to 800 cdls ft 10 Set the flash mode aperture switch to 8 11 Block any light from the photocell on the camera using a square of cardboard or other material 12 Depress the exposure button and observe the APERTURE meter 13 Record the 8 APERTURE reading and compare it to the STANDARDS Chart 14 Remove the tape form the focus
26. ades Open to Correct Sol 15 Cycle Opens Aperture S4 AC Close Power Up Complete S1 S4 CA Sol 2 to Power FFA FT Film S5 Closes Opens Power Up Ejected Closes Y DELAY lt gt FLASH DELAY FTO Flash we Flash Time Fires Out At Hight Light Stop Blades Levels Early Ambient Close Cameras will Exposure take Ambient Exposure does not apply to P configuration T1 and F SHUTTER MECHANICAL DETAILS Figure 2 9 The following paragraphs describe the manner in which the mechanical components of the shutter respond to either manual or electrical direction 1 When the operator prepares to take a picture he first must aim and focus the camera As he rotates the focus wheel to bring the split Fresnel SHUTTER FRONT HOUSING ASSEMBLY 1 REMOTE CONTROL SOCKET Si REMOTE CONTROL ASSEMBLY image into focus a cam molded into the rear surface of the focus wheel moves the component identified as the cam follower assembly The trim link coupled to the trim assembly is pinned to the cam follower in such a way that follower movement is also directly influenced by the setting of the trim wheel The trim wheel is the lighten darken control on the photocell LENE AND BLADE ASSEMBLY St HOUSING SCREW amp a gt Ae SOLENOID Ft FULLOOWN BAR SOLENDIDAD pay MOUNTING SCREW mane ae FOCUSWHEEL AETAINIMA BEREN FOCUS WHEEL Pivot Figure 2 9 Shutter exploded view 2 When an am
27. ak test 2 Check focus and trim wheel torque 3 Check trim wheel reset 2 teeth and front cover to shutter gap 4 Cycle camera 3 times at 5 0 and 6 4 volts with power pack C FINAL VISUAL 1 Check optical path 2 Fresnel cosmetics per standards chart Split image 3 Wafer and 3 eye lens 4 Entrance and exit pupil position 5 Focus camera at 8 performe aperture test D SHUTTER COSMETICS see specification sheet 6 Ambient mode tracking at 3 lights levels note current drain see specification sheet 7 Collimate at infinity 8 Flash mode tracking at 10 4 see specification sheet 9 Check flash system a Flash sequence with camera tester check counter rotation b Flash on zero 10 Inner frame bow 004 to 011 B OPERATIONAL SEQUENCE 1 Check camera latching 2 Erecting link grinding 3 Positive lock 4 Check front movement and latch a Check trim reset cam correct cam and condition b Light shield condition and movement c Light piping seal d Idler gear stacking e Outpout gear slippage 5 Check flash on dark slide power pack and flash simulator 6 Take flash pix at 10 4 check premature dark slide 7 Check for dirty rollers and film catcher spring 1 Chrome 2 Lens conditions 3 S1 button and photocell conditon trim wheel decal 4 S1 remote and flash socket condition 5 Shutter mounting screws missing or loose E CAMERA BACK 1 Shade blade
28. an 90 as shown in Figure 4 3 RAMCEL BRACKET BENT BRACKET Figure 4 2 Comparison of spread roll brackets 4 Close the front cover and recheck bend further if necessary 5 With the front cover open observe for a clearance between the latch and the 3rd idler gear 6 Observe that the stop pin Figure 4 3 is not resting on the outer plate when the front cover is closed When resting on the outer plate the latch front cover closing system will loosen from wear in a short time Make the following observation e Open the front cover and note the location of the front cover latch decal arrow e Close the front cover amp note the decal location The decal arrow should be closer to the bottom cover Figure 4 4 If not it is an indication of front cover looseness which should be corrected STOF PLN Figure 4 3 Bending the stop latch FRONT COVER OFEN FRONT COVER CLOSED Figure 4 4 Comparison of decal before and after front cover closure 1 Interference Between Front and Bottom Covers A few cameras may have an interference fit between the S7 actuator post and the edge of the bottom cover when the front cover is opened The problem has been traced to slightly oversize bottom covers Problem bottom covers have a mark PP 2 One method of correction is to bias the bottom cover and front cover away from each other to the limit of the screw holes In an extreme case you may be able to grind th
29. beint light exposure is being made all of the action just described takes place but does not affect the shutter action However when a flash array is inserted switch S2 in the flash socket programs the electronics to energize solenoid 2 The impact of this action on the movement of the shutter blades is described in paragraph F 4 but first the shutter blade actuation must be described as follow 3 When the ECM circuit powers solenoid 1 the solenoid plunger is pulled into its seat overcomming the opening spring force The plunger pulls the walking beam rotating it about 60 degrees Each of the shutter blades has a pin which engages a slot in the walking beam As the walking beam rotates it transmits its rotary motion to the shutter pins and drives the rear blade to the right facing the front of the shutter and the front blade to the left thus closing the light path of the picture taking lens and the light path of the photocell lens When the shutter is totally closed and the gear train has reached the point in the sequence at which the Fresnel carrier snaps up the exposure sequence starts The blades will proceed toward the fully open position and retrun to a closed position in the time interval dictated by the photocell and integrating circuit The blades may not reach the fully open condition if the illumination level is high or they may fully open for a period of time if the light level is low If a flash array is mounted the
30. ble However the light rays striking nearest the corners of the screen meet the screen at a more oblique angle than the rays striking near the center At this greater angle a larger percentage of the light is dispersed and less light is returned to the viewer Thus on a matte screen image the corners would appear darken than the center The Fresnel screen is designed to overcome this problem The screen itself is a sheet of plastic upon which are impressed series of concentric rings much like the grooves pressed into a phonograph record Figure 2 3 instead of having a vee shaping however the grooves in the Fresnel screen form a saw tooth with a tooth angle increasing slightly with each successive groove in such a manner as to complement the decreasing angle of the light ray The saw tooth flattens out completely at the exact optical center of the screen In the SX 70 camera the optical center is not the geometrical center of the screen The surface of the screen is silvered to provide optimum reflectance The result is a brilliant viewing image evenly illuminated from corner to corner For the reader who is familar with the use of a Fresnel lens used in conjunction with a ground glass focusing screen or a Fresnel ground focusing magnifier it must be noted that these are transmission devices while the Polaroid screen is a reflecting medium Otherwise the brilliance enhancing properties are the same A suitable analogy would be
31. ck encapsulaetd batteries To prepare the camera for picture taking hold the camera in the left hand pull straight up on the serrated portion of the viewfinder housing Figure 1 2 this action releases latches which in turn allow the main body of the camera to raise into operating position When the camera is fully opened the interlock switch S6 located at the left rear corner of the mirror cover is closed and the battery is connected to the camera electrical circuit Figure 1 4 Figure 1 4 S6 with contacts closed Figure 1 5 Inserting film pack 2 Loading the Film pack The front coverlatchis located on the right side of the camera just inside the rim of the bottom cover assembly Pressing down on this yellow latch releases the front cover which drops down to expose the film chamber With the cover open a film pack can be inserted or an exhausted pack can be removed A fresh film pack is loaded into the film chamber observing color coding Figure 1 5 Under certain circunstances a partially used pack could be inserted but this action will cause some deviation in the normal counting sequence The battery is a part of each film pack and the two exposed terminals on the pack engage two contacts within the film chamber as the pack is inserted 3 Starting the Automatic Mechanism With the film pack in place the front cover can be closed It must be fully closed and latched MATCH COLOR CODE ON PACK WITH COL
32. condition scratched distorted 2 Shade blade movement gap between blades 3 Concave mirror condition color code refurbished only 4 Repair techs scribe data and repair center code 5 Gear train cover 6 Bottom cover window and condition 7 Cable cover cable camp cable restrainer conditon position 8 Cable spring hook on 9 Boot retainer tabs in place 10 Cracked broken hinges 11 Shutter hinge bracket pivots and gap 0125 max 12 Leather and chrome cosmetics 13 Set lens at infinity F PICTURE EVALUATION 1 Baffle in pix aera 2 Cracked dirty taking mirror 3 Incomplete coverage front cover related 4 Color code and FTC label refurbished camera only POWER SUPPLY 11775 e i mi ae FILM PACK SMULATOA ARTEL Figure 3 1 Film pack simulator and power suplly C TEST EQUIPMENT OPERATION Checkout the SX 70 camera requires the use of several pieces of test equipment The purpose of this section is to instruct you in the proper use of this equipment 1 Power supply and pack simulator Figure 3 1 In use the system subsitutes for the film pack giving a steady reliable source of power a Plug the pack simulator into the power supply being careful to observe polarity ground is negative b Set the power supply switch to VOLTS and turn the supply ON c Adjust the output to the desired volatge 5 8v normal NOTE Except on Lafayette made unit
33. d 1 again in the power down condition and starting the motor to eject the exposed film NOTE the lenght of the timing cycle is determined in amount of the light reaching the photocell If there is insufficient light to correctly operate the integration circuits the system will automaticall terminate the exposure within 14 to 30 seconds j When in the previous step the solenoid closes the shutter blades and drive motor is energized the gear train resumes its sequence with the following results 1 The film pick feeds the exposed film to the spread rolls 2 At the end of its travel the pick uis held in its forward position by the pick latch 3 Film moves through the spread system 4 The recock gear cam proceeds to retrun the recock ran which through the bell crank moves the Fresnel carrier down 5 The recock ram closes switch S3 to prepare for another exposure 6 The light stop opens the optical path to the viewfinder 7 The film completes its passage through the spread rollers The front cover idler gear meshing with the gear train powers the top roller which drives the film through the exit slot 8 The Fresnel carrier when fully scated is held by the recock ram 9 The pick latch releases the pick and the pick returns to its starting position 10 The recock ram closes S5 to cause the ECM to shut off and dynamically brake the drive motor k If the operator has removed pressure from exposure button
34. d target so no additional equipment is needed 2 Turn on the collimator light 3 View the added target with the focu wheel set to infinity 4 Compare the observed conditions with the examples shown in Figure 3 4 As indicated best case the upper part of the vertical line should be aligned with the bottom part of the line or it may be displaced to the right If displaced to the right acceptable it should still be touching the lower part of the line 5 If the upper part of the line is displaced to the right so far that it does not touch the lower part of the line or if it is displaced to the left out of tolerance the tolerance levels are exceeded and the camera must be rejected Corrective procedures are outlined in Section IV b Collimation of Non Split System Image Viewing 1 Turn on the collimator light source LEFT SIDE OF TOP LINE Ad 6 6L TI OUT OF TOLERANCE Figure 3 2 Typical collimation conditions BEST CASE ACCEPTABLE RIGHT SIDE OF BOTTOM LINE 2 Open the camera front cover slide the camera onto the horn of the collimator Make sure that the camera is all the way on the horn so that the camera is captured by the spring latches 3 Swing the collimator infinity lens to its vertical position Be sure the 8 lens is not in the viewing path 4 Look into the camera viewfinder while turning the focus wheel counterclockwise until the image appears sharp Look at the collimator
35. detail in Section II of this manual When the exposure is made the image must be transferred from the viewing system to the surface of the film in accurate focus To accomplish this the shutter closes and the viewing screen swings out of the optical path which is then diverted by a mirror to the film surface These two paths are described in greater detail elsewhere in this section The exposure is made following the viewing screen mirror swing The screen then returns to the viewing position and the automatic mechanism ejects the exposed sheet of film development takes place outside the camera and can be observed by the operator As soon as the print is ejected the mechanism completes its MIRAGOR COVER _ ERECTING LINK BOTTOM COVER LIGHTENWODARKEN CONTROL cycle to prepare for the next exposure Following thenth exposure the flash circuit is inhibited until a fresh film is inserted Normal operation will resume when the camera is reloaded B CAMERA OPERATION The following paragraphs describe the electro mechanical events that occur in normal operation the purpose of this desciption is to acquaint the reader with the manner in which the various functions are accomplished Detailed analysis at component sub assembly level appears in Section Il 1 Opening the Camera When the SX 70 is folded an interlock switch S6 removes all battery power from the camera mechanism to prevent any drain from the film pa
36. e collimator and continue with step 6 IDLER GEAR ADSUS TING _ SCREW SPECIAL TOOL 11029 Ie we k i SPRING LOADEO SYSTEM ON COLLIMATOA Figure 3 5 Disengaging the idler gear 6 Verify the infinity setting Do this by observing the vertical line target through the collimator infinity lens and the camera optics The line should be straight within the tolerance in Figure 3 4 7 Swing the collimator infinity lens back down to its horizontal position out of the viewing path of the camera Turn the camera focus wheel to the 10 4 setting 8 Look through the camera and observe the vertical line target Compare the observed image with Figure 3 4 to determine if the camera is within specifications NOTE There is no separate close focus adjustement on the camera if the focus wheel has reached its stop before maximum resolution is achieved return to the infinity check If there is any tolerance at that setting readjsut the infinity setting as close as possilbe to the focus wheel stopping point and recheck the close focus If it is still impossible to obtain a sharp image the lens is defective and the shutter must be replaced NOTE The foregoing tests assume that when the camera is operated the viewing mirror Fresnel carrier reaches the correct attitude during the exposure cycle If the lens has been correctly collimated the only check possible of actual picture definition is to expose fi
37. e mirrors are used in the SX 70 optical system When a picture is being taken the Fresnel carrier is raised This places the 4 edges taking mirror into the optical path and light is reflected onto the film plane The taking mirror is mounted on the Fresnel carrier on the side opposite the Fresnel screen The second mirror the 6 edges viewing mirror is used in the optical path twice First the light rays entering the camera from the taking lens are reflected onto the Fresnel screen by the viewing mirror secondly the operator views the image on the screen with light reflecting off the viewing mirror Figure 2 1 The viewing mirror is located on the underside of the mirror cover assembly 4 Flare baffle The flare baffle Figure 2 2 is a spring loaded plate which springs up when the Fresnel screen moves into the picture taking mode In this state light is prevented from passing through the lens directly onto the film without first being reflected off the taking mirror This prevents hotspots from appearing on the finished picture When the Fresnel carrier is in the lowered position the flare baffle is held down out of the optical path E CAMERA ELCTRONICS 1 General The SX 70 is unique both in its principles of operation and its functional design It can be considered as aan electronically controlled mechanical device An electronic control module substrate or ECM contains all of the electronic components with the
38. e open A spring openong spring holds the shutter blades wide open Figure 1 10 The lens thus provides maximum viewing focusing brilliance Solenoid spring action is discussed in detail in the next section of this manual H e kh h a m a s T L 28 Ss l j RE SR r e E 1 OPENING SPRING Figure 1 10 Shutter blades held opened When the release button is pressed a switch S1 closes Figure 1 11 A and B and applies operating power to the shutter As soon as power is applied to the shutter solenoid 1 is energized and rapidly moves the shutter blades to the closed position Figure 1 11 A Location amp Arrangement of internal parts 7 RED BUTTON OFEN Figure 1 11 B Operation When the solenoid has reached the end of its stroke shutter closed it no longer requires maximum current to hold it at that postion Switch S4 located on solenoid 1 closes CB and activates an electronic circuit called the POWER DOWN CIRCUIT This reduces power nny ir eee Oe ae 1 Nas ehh ahh P A to an adequate level to hold the solenoid after the high current circuit has completed the solenoid operating function and switches on the motor drive circuit Thus the shutter will remain closed with minimum battery drain Light entering the lens is now cut off and the reflex mirror is swung upward to picture taking position The electronic latch activated by Opening S5 assures that the sequence will be complet
39. e required clearance from the S7 actuator post in the front cover Correction of this interference problem should only be at customer request since the problem diminishes with use 1 Top Spread Roll Looseness There have been instances of the top spread roll popping out ofthe spread system To eliminate the problem the new spread rolls have a cap welded on the end opposite the drive gear Figure 4 5 The cap captures the spread system frame Figure 4 5 New spread roll configuration When making any repairs requiirng replacement of either the spread system or the front cover assembly replace the old spread system with a new one If you install a new spread system in an old front cover you must remove the light seal before installing the new spread system The new light seal is adhered directly to the spreader before the spreader is installed in the front cover 4 Replacing the Light Shield Cam A manufacturing change to the Trim Assembly was made to overcome erratic action Part of this change was to revise the cam on the light shield This cam resets the Trim Assembly each time the camera is closed Figure 4 6 compares the old shutter and cam with the new shutter and cam The cam on the light shield of the front cover has been made wider and deeper The tang of the trim reset lever shutter is now a flat bar about 1 16 of an inch wide and appears off center It is a brass or flat black color All replacement shutters wi
40. e shutter has been unsoldered from the camera If repairs and or replacements are indicated the procedures are described in Section IV NEW CAMERA FRESNEL STANDARDS ALL BISCLAM AEE Mad ACCORT ktb SRLS bt Stee At f i aii FV fase A fats vite ORE af i F OE TH pLENTINLE 5 A ASMA TL FCELTCH or IT Tee SCRATCEER Tm iret CAMERA BS OAL rdt CAI AT HHT AAG AN bE wu WWA THAN Mite wast AT AS LE i A TE PCEATET ok PIAT TW SCLiTcunl tm Pitt Figure 3 16 Fresnel standards chart CLiae Ticwrts Figure 3 18 Flex circuit terminal locations 1 Camera Shutter Isolation To expedite the repair procedure it is essential that the malfunction be isolated to either the camera back or the shutter as early as possible in the troubleshooting procedure The sequence should not be considered inflexible however a Disassemble the camera to the point where the terminals on the flex circuit are accessible Figure 3 17 b Tack solder a 1000 ohm 1 2 watt resistor across the VCC and NPN terminals as shown This procedure does not apply to mid cycle shutdown Refer to the Failure Analysis Charts NOTE One 10 pad flex circuits these are the TP6 and TP30 terminals One 8 pad circuits these are TP4 and TP21 terminals One 7 pad flex circuits where the PNP pad is eliminated the NPN terminal is located directly adjacent to the VCC terminal Refer to the inserts in Figure 3 17 to locate the proper terminals
41. ed even if the operator removes his finger from the exposure button S41 When the mirror swings up a mecchanically operated switch S3 actuates a Y delay circuit 40 milliseconds Figure 1 12 so that the shutter will not function until the mirror bounce has subsided At the end of the delay period the electronic circuitly removes the power from the soleniod and the opening spring sets the shutter blades in motion toward the full open position At the same instant an electronic switch opens and starts the integration cycle The integration cycle is that period during which the total amount of light intensity and duration reaching the photocell is transformed electronically to regulate the lenght of time the fiml is exposed The shape of the opening in the shutter blades and the FRECOCK ARAM 5 CONTACT Ly a _ Figure 1 12 S3 Being opened by recock ram motion of the blades is such that all of the factors involved are continously variable throughout the exposure period this fact however is a design consideration and should not confuse the theory of the shutter operation from a maintenance point of view When the camera completes all off its automafed functions and the release button has been released all voltage is removed from solenoid 1 and the shutter opens in preparation for the next exposure It should be noted that under extremeley low light conditions the shutter will closed completing the exposure cycle
42. er frame meets the outerplate To make an effective repair when this happens replace the original screw with an oversize screw or insert a thin sliver of plastic into the stripped hole before the original screw is returned A FRONT COVER SPREAD ROLL ASSEMBLY The spread rolls in the SX 70 camera are gear driven by the main gear train Thus in addition to wear or damage to the rolls it is possible to encounter wear and or damage to the drive gear Regardless of the nature of the malfunction the complete assembly must be replaced The following paragraphs describe the replacement procedure Removal 1 Erect the camera to picture taking configuration 2 Open the front cover by depressing the front cover release latch on the right side of the camera bed 3 Apply pressure to the side of the cover adjacent to the cover hing aera Press toward the gear train side of the camera This will release the front cover On newer models detach the front cover from the right side gear train side only 4 inspect and clean the rollers and gears with a Q tip moistened in water If film developer is observed under the light shield or in the film catcher spring aera the front cover housing must be repaced 5 If necessary as described above replace the front cover housing and test 6 If the spread roll assembly is to be removed strip the leather from the cover Start pulling the leather from the back and pull toward the film exit Do
43. era tester MANUAL FUNCTION TEST SEQUENCE Test Mode Shutter Response Close S6 S7 No reaction Blades open motor off Press and release S1 button to check for mechanical binding Observe current drain AMBIENT Exposure Remove flash array from Mode shutter Close S1 Blades close motor runs Open S5 Blades close motor brakes Open S1 Blades close motor brakes no reaction Open 3 Blades open then close motor runs exposure time dependent on amount of light to seen by photocell Close S3 Blades close motor runs Close S5 Blades open motor brakes S8 Dark Slide eject mode Close S8 Blades open motor brakes no reaction Close S6 S7 Blades close motor runs Flash Array inserted Open S5 Blades close motor runs Open S3 Blades close motor runs no flash Close S3 Blades close motor runs Open S8 Blades close motor runs Close S5 Blades open motor brakes Flash Mode flash array Close S1 Blades close motor runs inserted into shutter Open S5 Blades close motor brakes Open S1 Blades close motor brakes no reaction Open 3 Blades open then close small aperture flash fires motor runs Close 3 Blades close motor runs Close S5 Blades open motor brakes Open F1 thru F5 Bulbs fire insequence consecutively repeating above test between each switch opening S9 Empty film pack Close switches F1 thru F5 mode Close S9 Blades open motor brakes no reaction Close 1 Blades close motor runs Open S5 Blades close motor brakes
44. es the ability of the viewer to focus the camera in dimly lit aeras CENTEA OF FRESMEL SEIER SEEE FRESNEL GROOVES ENLARGED SIDE VIEW 2 Viewfinder The viewfinder optics consist of an eye lens a concave mirror and a wafer lens Figure 2 4 As in all simple optical system a certain amount of distortion is inherent in this design A small wafer lens is introduced into the viewfinder optical path to limit to angle of acceptance and thus reduce distortion The size of the lens opening is large enough to provide acceptable viewing brilliance and at the same time small enough to be easily closed when the camera is in the exposure mode On earlier models a rectangular mask called a stigmatic pupil takes the place of the wafer lens Figure 2 4 Wafer lens assembly Ignoring the shutter functions momentarily when the operators presses the exposure button the Fresnel carrier swings away from the film plane and comes to rest in front of the viewing mirror During the moment of the Fresnel carrier and until it returns to its initial viewing position a flexible light stop closes a path between the viewfinder and the inner camera to prevent light trough the eye lens from reaching the film The movement of the spring driven Fresnel carrier is accomplished by the motor driven gear train The details of the automated action are described in the discussion of the electro mechanical assemblies 3 Mirrors Two first surfac
45. exception of the motor control MCC integrated circuit and the flash fire assembly FFA Because the ECM is located inside the shutteur housing it becomes identified as part of the shutter Figure 2 5 It should be noted that all of the camera automation is controlled by the integrated circuits in the ECM SHUTTER ASSEMBLY ECH ELECTRONIC CONTROL MODULE Figure 2 5 ECM Electronic Control Module The entire ECM rather tna its individual integrated circuits is used as a remplacement item For that reason the theory of operation and analysis techniques presented in this manual have prepared in such a way that the repairman can relate a specific camera failure mode to an ECM function 2 Switch functions a Switch S1 is actuated by either the red shutter release button or remote control cable release It is operated by the photographer and it causes the camera to run through a complet exposure film delevery cycle ie li Figure 2 6 SX 7 0 Switch locations uy lui tk b Switch S2 places the circuitry into the flash mode Switch S2 si closed when the flash bar is inserted into the FFA on the top of the shutter housing It commands the integrated circuit in the FFA to select the first unused flashbulb and to fire the bulb It also enables the ECM to energize solenoid 2 which limits the opening of the shutter blades so that flash exposure will be determined by flash to subject distance When the solenoid 2
46. fter a new pack inserted e S8 opens counter set to 10 CLOSED BY OPERTOR Solenoid 1 power up Shutter starts to close Shutter close S4 SWITCHES AC to BC Cam rotates Mirror released OPENS Motor braked Cam stopped at 20 Electronic latch ON S1 may be opened Mirror continue to rise OPENS 26 34 Y delay activated Mirror at rest POWER RELEASED FROM SOLENOID 1 Shutter starts to open S4 SWITCHES BC to AC Starts integration ambient Shutter at full open f 8 16 EXPOSURE COMMAND SIGNAL COMPLETE Solenoid 1 power up Shutter starts to close Shutter close S4 AC BC open S4 SWITCHES AC to BC Motor starts Fresnel starts down Cam moves from 20 position Solenoid 1 power down Mirror carrier starts to drive counter CLOSES CLOSES Electronic Latch off Motor stops if S1 closed Solenoid 1 remaing in power down Shutter opened provided S1 is open Counter set to next position FLASH S2 Closed if flash array inserted S1 T 0 7 S4 BC 200 ms max 09 ol Solenoid 2 power up S2 closed op oO pen Solenoid 2 power down Y Delay 40 5ms End Y Flash delay FD circuit actived Sms gt gt S4 AC t j Switches power to falsh circuit S2 closed 20to35ms 4 p 0 iL Solenoid 2 back onf power off triggers FF circuit FF at the end of flash delay FD ST 2 shorted out time FLASH out interval FT initiated 25 to 34 ms FT Note 1
47. ghts have flashed k Repeat step d though j The lights should flash five more time Press S1 m Observe that no light flashes This confirms proper operation of S9 6 Manual Function Tester Figure 3 10 NOTE The Manual Fucntion Tester 11959 is updated version of the Camera Back Simulator 11775 The basic difference between the two pieces of test equipment is that the simulator relies on an external power supply while the function tester ahs a built in power supply The steps listed in paragraph b Test apply to both units Remember if the shutter tests satisfactorily at 5 volts the test must be repeated at 6 4 volts Set up 1 Using a VOM check for shorts on the shutter before setting it on the tester Not necessary for plastic base shutter Check between and points on the substrate and the casting There must be no shorts 2 Set power supply to 5 0 volts If simulator is being used connect to power supply set supply to 5 0 volts and switch supply from VOLTS to AMPS 3 CLOSE tester switches thru F5 4 OPEN tester switches S1 S6 S7 S8 S9 5 Clamp shutter cable in the connector and insert flash bar connector into the shutter FFA 6 Set shutter lens to 10 4 and trim wheel to full dark S2 S3 S5 F1 7 Proceed with testing as indicated in table below If shutter tests ok at 5 0 volts retest at 6 40 volts Tr TER SH UTTER CASL PROBES oe Figure 3 10 Manual cam
48. he focus wheel to 10 4 b Hold the camera at arm s lenght with the taking lens toward you and a bright light source behind the camera c Look through the taking lens closing one eye Observe the entrance pupil in the lens d Raise the front of the camera about 10 and note two bright circles against a dark background Both circles should be verticaly positoned 050 from the center as shown in Figure 3 14 B e If the circles are not centered vertically Figure 3 14 A perform the erecting link adjustment in section IV f If the circles are displaced horizontally Figure 3 14 D make the side to side adjustment of the Fresnel carrier which is included in Section IV 050 FROM CENTER IS ACCEPTABLE VERTICALLY ALIGNED 8 HORIZONTALLY ALIGNED D 3 Concave Mirror Distortion Check a Focus on a target which presents a clear vertical line for example a door frame b Scan the camera horizontally c If the mirror is not distorted the vertical line seen in the eyepiece will vary at the camera is scanned At either side of the field the line will be bent while in the center of the field the line will be straight see Figure 3 15 A d If the mirror is distorted the vertical lines change more graphically as the image si scanned andone or several reversals of direction of bending may occur Figure 3 15 B e A telephone directory page at a distance of 2 feet may be used to check dist
49. he shading extends beyond the aera top or bottom of the Fresnel shown on the chart the Fresnel si not acceptable e Examine teh split image circle by comparong it against teh examples shown on the chart If the shading on the split is greater than shown or if there is more than one dig pit stain or scratch on the split the Fresnel is not acceptable the Fresnel must also be rejected if the blemish on the split is larger than any shown on the chart 5 Collimation For the collimation procedure refer to paragraph D Test Equipment Operation E USE OF ANALYSIS CHARTS The following charts should be used to identify and correct faulty camera operation It will seldom be necessary to consult every chart Only those related to a particular malfunction should be consulted In some cases the customer s complaint will be sufficiently specific to lead you to a particular chart In other cases the preliminary inspection procedure at the beginning of this section will provide usefull information to lead you to a Chart In all cases the fault analysis charts present the logical sequence of checks and remedial procedures These charts are divided into three parts one CAMERAANALYSIS for problem analysis when the camera is completely assembled two OPTICAL ANALYSIS for analysis of the viewfinder parts three SHUTTER ANALYSIS for detailed shutter analysis The SHUTTER ANALYSIS charts should be used only after th
50. ich must be removed rotated and reinserted after the fifth lamp has been fired Figure 1 9 Insering a flash into the flash socket closes switch S2 in the socket This action sets up the shutter electronic circuit to permet firing of the flash lamp A follow focus mechanism coupled to the lens focusing system arrests the shutter blades at an opening related to camera to suject distance NOTE On early camera models the light measuring circuit remains active even with the flash bar inserted into the socket If the circuit determines that there sufficient ambient light an exposure will be made without the flash Cameras with P configuration or later shutters do not have this light measuring feature in the flash mode Regardless of the ambient light level the circuits will fire the flash when a flash bar is in the socket unless of course the lamps have all been used If the array has been exhausted the shutter will complete the exposure cycle without flash Maximum exposure duration is 30 seconds When the exposure counter reaches 0 empty the camera will not fire a flash lamp even though unused lamps remain in the bar The previously discussed deviation associated with the exposure counter is applicable to the flash functions If an unusedlamp is in position and if a partially empty film pack has been reinserted the camera will continue to fire lamps after the last sheet of film has been exposed until the counter reache
51. in 14 to 30 seconds whether a suitable exposure has produced or not C SHUTTER DESCRIPTION FLASH MODE The special ten shot flash bar is equiped with a shorting bar so that when the bar is inserted two contacts within the camera is shorted This switch is identified as S2 When S2 is closed the shutter electronic circuit detects that a flash bar is in place and ready for firing In general the sequence of the functions remains the same as for ambient light operation with the following exceptions J CONTACT of CONTACT mechanical device identified as the interceptor connected to the lens focusing mecchanism Figure 1 13 A the interceptor is moved as the lens is focused regardless of whether ambient light or flash pictures are being taken When flash bar is in place S2 closed and the gear train opens switchs S5 Fighure 1 14 solenoid 2 is energized and pulls the interceptor into position to phycally restrict the shutter blade travel Figure 1 13 B Since the interceptor is controlled by the focusing mechanism the shutter opening is related to camera to subject distance thus compensating for the flashbulb to subject distance to give proper flash exposure As a solenoid 1 de energizes switch S4 moves from the CB position to the CA position This switch conects VCC to the FFA TO SUASTRATE Ts FROM SUBSTAATE fhe os A J Jaa et ff l aw f My 4 FiN SOLENOID 2 ACTUATCA LINK NOT ENMLAGIZEO Fig
52. inear lens elemet movement Operation is by means of a geared focus wheel at the top of the shutter housing There is no manualy adjustable diaphragm associated with the SX 70 lens D VIEWING AND EXPOSING SYSTEM When the camera is erected to picture taking configuration the subject can be viewed through the collapsible viewfinder Figures 2 1 and 2 2 show the two optical paths in the camera Note the direction of the arrows Reflected light from FAROB LI MIRADA TAKING LENS TAKING KWAROR IWMHOER FRESNEL TAKING MIRROR f FiLM SURFACE Figure 2 2 Viewfinder optics exposing the subject passes through the camera lens and is reflected by the viewing mirror on the inside surface of the mirror cover to the Fresnel viewing screen The entire subject image is now reproduced on the viewing screen At this point viewfinder optics must be employed for focusing The optics must transfer the image from the viewing screen to the eye done by the parabolic mirror and the viewing mirror and must present the image in a fairly sharp contrast to permit proper focusing done by the eye lens and parabolic miror LIGHT SEAL F G LARE BAFFLE 1 Fresnel Figures 2 3 A and 2 3 B The special Fresnel pronouced Freh nell screen is employed to enhance the viewing image by increasing the brightness and defintion If a matte white surface were substituted for the Fresnel screen an image would still be visi
53. is pressed and the exposure cycle is initiated full battery power is delivred to solenoid 1 closing the shutter Once the solenoid plunger is seated it no longer requires as much power as was originally needed to overcome its static inertia Switch S4 therefore closes the S4 CB contacts to the ECM and the electrical power to the solenoid coil is reduced to the power down value which is sufficient to continue the exposure cycle yet low enough to conserve battery drain Whenthe switch S4 CB contacts closed transfers to the ECM it sends power to the drive motor and operates the gear train When S4 is actuated CB contacts closed it also disconnects power from the FFA flash circuitry This action prevents 3 CONTACT CONTACT INSULATEG BASE BOARD Figure 2 8 S4 Switch operating configurations damage to the circuit in the event that flashbulb becomes short circuited after it is fired e Switch S5 normally closed at the beginning of the exposure cycle like S3 is located in the gear train and actuated by the recock ram Figure 2 7 When the gear train rotates to appropriate point in its cycle S5 opens and removes power from the drive motor applying dynamic braking voltage to stop the gear train quickly The ECM reacts to this command in such a way that exposure cycle continues completion even through the operator has released the exposure button S1 After the exposure and when the Fresnel carrier returns to
54. ition using the trim reset cam and focus teh camera at infinity 4 Slide the camera fully onto the horn 5 Select the light level desired on the Comparalumen and slide the horn up against the appropriate window Position the horn so that the locating pad on the front of the horn touches the window 6 Insert a remote shutter release cable into the socket on the right side of the shutter 7 Rotate the RANGE switch on the electronics module to the SX 70 EXP position 8 Lift the EXPOSURE APERTURE MODE switch to the EXPOSURE position 9 Press the remote shutter trip button and read the exposure on the meter 10 Return the EXPOSURE APERTURE MODE switch to the RESET position d 10 4 Aperture Measurement NOTE This measurement must be preceded by steps 1 throught of the Ambient Exposure Measurement procedure then complete the following 1 Rotate the camera focus wheel to the 10 4 setting 2 Insert a used flash bar into the camera flash socket and position the spring clip Supplied with the tester over the flash bar so the photocell is covered 3 Select the 800 cdls ft on the Comparalumen and position the camera at the right hand screen 4 Rotate the RANGE switch to the 10 4 position 5 Place the EXPOSURE APERTURE MODE switch in APERTURE position 6 Press the remote shutter trip button and read the aperture in the relative stops on the meter 7 Return the EXPOSURE APERT
55. ll be the new type The improved shutter will also have a cut out aera larger and squarer in shape than the older version END CAP en Cy i A OLD SHUTTER CAM La E A e amp MEW SHUTTER amp CAM Figure 4 6 Front cover light shield cam When a new type shutter is installed the cam in the light shield must be inspected and changed if necessary The new cam should be installed in the same place and manner as the old cam Figure 4 7 Remove the old cam uising an x acto knife to cut the plastic rivets Place the new cam in the same position making sure the cam lip goes over the edge of the light shield as shown and the pins through the four holes When assembled apply heat enough to peen over the ends of the pins projecting through holes thus staking the unit in place If new cam are not available it will be necessary to install a new front cover assembly Figure 4 7 Replacing light shield cam B MIRROR COVER BOOT ASSEMBLY The mirror cover assembly consists of the mirror cover the boot and the viewing mirror Because of its construction ti is not feasible to disassemble the mirror cover assembly itself and therefore whenever one of its major components fails the entire assembly is replaced The mirror cover could sustain damage in the form of cracks or broken hinges or overall distortion The boot could be cut torn and damaged by wear The mirror could be loose or displaced in its mounts broken or its s
56. lm 3 Comprehensive Testers Figure 3 6 and 3 7 There are two models of Comprehansive Testers available for semi automatic testing of the SX 70 camera The earlier model Comprehensive Tester Model A consists of three interrelated units the lightbox the electronics module and the power supply Figure 3 6 Comprehensive Tester Model B Figure 3 7 also consists of three interrelated units the Comparalumen calibrated ligh source the electronics module and the mounting horn or holding fixture The purpose of both tester models is to check the dynamic operating functions of the camera A detailed description of the later tester is available in a technical manual titled Model B camea tester This section will deal only with the operating instructions for the tester MODEL A CAMERA TESTER a Set up Before testing the camera perform the following set up procedure 1 Calibrate the tester daily Record the calibration reading in a log If the test equipment is suspected of poor performance calibrate more frequently and repair if necessary 2 Remove the front cover from the camera 3 Set the L D control to the mid range position usiong the trim reset cam and focus the camera at infinity 4 using the S7 actuator close teh s7 switch 5 Allow the tester to warm up for a period of 30 minutes POWER SUPPLY ELECTRONICS MODULE LIGHT BOX Figure 3 6 Comprehensive tester CALIBRATED LIGHT SOURCE EL
57. nnects the battery to the camera circuitry b The operator opens the front cover Switch S opens and removes battery power from the camera c The operators open a film pack when the previously used film pack was removed a EMPTY FILM PACK Figure 2 8A S8 S9 Exposure counter switches SWITCH FUNCTION TABLE closes Initiates exposure cycle and causes circuitry to take and deliver the pictures Connects circuitry to take flash pictures opens CA closes level CB closes closes opens Initiates Y 40 milliseconds delay Power down solenoid 2 in the flash mode Controls power to solenoid 1 drop current to holding Signals the ECM to start the motor e Connects the battery to the electronic circuitry when the camera is open to use e When the camera closed cuts power from battery When S8 is also closed it provides power to the camera when the front power is latched for dark slide eject Also acts as an interlock during normal picture taking Enables with S7 closed the circuitry to eject dark slide Opens again after the dark slide is ejected Prevents firing flash if film pack counter is on 0 5 opens closes Stops motor both by closing and opening depeending upon sequence of action and internal circuitry mechanical coupling device set the exposure counter to the position just before the first exposure and closed S8 but since S7 has removed all battery power no action occ
58. not start at the film exit Take out two screws which secure the spread rollers to the inside of the front cover and remove the roll assembly from the cover Installation 1 Position the spread roll assembly in the front cover so that the gears will mate with the main gear train when the cover is in place 2 Install and tighten the two retaining screws used to secure the rolls NOTE A new sSefl tapping square socket head coarse thread screw PIN 7 05564 is used to effect a repair of stripped thread in the front cover assembly when installing a spread system assembly If the hole was stripped during disassembly the new screw will permit easy reassembly This screw is standard on newer cameras A new square screwdriver tool bit PIN 11867 is available from Waltham Parts Dept 3 Position the front cover housing on the camera 4 Install the decorative leather covering Make sure the film exit is not covered by the leather 5 Install the front cover by squeezing the sides of the cover just enough to engage the hinge on the pivot points of the bottom plate 6 Close the cover and check the camera for proper operation NOTE If mishandling or dropping of the camera causes breakage of the extruded metal studs used to secure and pivot the front cover no repair is possible Must replace the inner camera back assembly Figure 4 7 illustrated the studs mentioned Figure 4 1 Front cover hinge studs Repairs Adjs
59. ocus wheel during this delay period if the ambient light level is sufficiently high to cause triggering of the integrating circuits the exposure will be completed and the shutter closed before the firing voltage reaches the lamp and the lamp will not be fired At the ends of the flash timing interval the circuit energizes solenoid 1 the shutter closes and the sequence proceeds as in the ambient light mode If the bulbs in the flash bar are all used when the operator attemps to make a flash exposure all of the previously described circuitly will function up to the actual firing of the flash lamp Since there is no lamp to ignite no flash firing current will be drawn There will be no output signal from the flash sequencing circuit and an ambient light exposure will be made On cameras with P or later configuration shutters the result will be a black picture unless the ambient light level is high enough to give an exposure this is caused by the fact that P and later configuration shutters have no integrating function as long as a flash bar is inserted in the socket Early cameras have a twenty second time out period even with a flash bar inserted in the socket Therefore if the flash bar is exhausted a properly exposed picture will result if the ambient light is great enough to produce one in twenty seconds ll THEORY OF OPERATION A INTRODUCTION A general description of the camera and the sequence of its func
60. ograms the ECM to complete the cycle even though the operator has released the exposure button after S5 is open NOTE there would appear to be a contradiction between this step and the step j 10 below wherein closing of S5 performs the identical function i e Stops the motor and applies braking S5 is able to perform in this manner however because the circuit gate to which it is connected is in a different condition during each of the steps g While the Fresnel carrier was moving up prior to motor shutdown the recock ram opens switch S3 When S3 opens it signals the ECM to initiate a 40 millisecond delay in the sequence This amount of time prevents a picture from being taken until mirror bounce has subsided h At the end of the 40 millisecond delay period the ECM removes power from solenoid 1 and the shutter opens Simultaneously the circuit starts timing the exposure integration The integration components of the ECm are controlled by the amount of light received by the photocell At this time the flash delay section of the ECM is made ready but will not function unless a flashbar has been plugged in to close switch S2 i When power is removed from solenoid 1 and the shutter begins opening the actuator on the plunger returns switch S4 to its original condition CA closed When the exposure timing cycle is complete power is returned to solenoid 1 and the shutter closes opening CA closing CB placing solenoi
61. on solenoid 1 pulls in the follow focus pin disengages from the interceptor and the solenoid 2 plunger returns to it original position under the force of the interceptor hinge spring 6 Since the photocell components are contained within the shutter housing they are included in this discussion A lens is employed to focus the reflected light from the subject on the photocell A second pair of openings in the shutter blades control the amount of light received by the cell as previously described A variable neutrality density wedge system is employed to provide lighten darken adjustements Trim assembly The operation of this control differs slightly from those used on other Polaroid cameras When the camera is folded a cam on the shield of the front cover strikes a release lever on the lighten darken assembly and returns the trim adjusting wheel to its center normal position The trim wheel is automatically centered when the camera is closed 7 To compensate for any variations in individual photocell characteristics a neutral density filter is selected and installed in front of the photocell lens during assembly A calibration must be performed and a filter of correct density installed any time the ECM requires replacement G FILM PROCESSING COMPONENTS The basic theory of the film processing method remains unchanged from previous Polaroid system That is the developping chemistry is encapsuled in a pod on each sheet of
62. or leaks Note the location of any light leaks You may see a small amount of light in the aera where the boot joins the shutter housing This is light emanating from the substrate and is normal Allow the camera ON OFF cycle completion and remove the fixture 4 Turn off the power 5 Repair any light leaks noted in the previous testing If light leaks reparis are made retest the camera 5 Flash Simulator Board Figure 3 9 The Flash Simulator Board provides a quick easy method for checking the flash firing capability of the SX 70 camera Figure 3 9 shows the board which contains five light emitting diodes LED five resistors and five toggle switches Providing the interface with the camera socket is a hot shoe assembly which reduces wear on the board contacts Use the simulator as follows a Insure that all switchers are in the position shown down b Insert a film pack or film pack simulator into the camera Operating voltage is 5 0V to 6 4V Figure 3 9 Flash simulator board c Install the flash simulator board into the camera flashbar socket in the same way as a flashbar would be installed d Press the red exposure button S1 e Observe that LED 1 flashes f Flip switch S1 up g Press the red exposure button h Observe that LED 2 flashes i Flip switch S2 up j In like manner continue pressing the red exposure button and flipping the corresponding switches up until all five li
63. ortion The white pages have high contrast fine detail and uniform printing f The frame around the viewfinder may appear non sysmmetrical about the vertical axis A normal mirror will appear to be sysmmetrical about the axis Figure 3 15 C VIEWFINDER A IMAGE GOOD BAC Figure 3 15 Identifying distorted mirrors 4 Fresnel Quality Check The Fresnel screen must be examined for blemishes shadows dirt scratches etc A standards chart Figure 3 16 is available for determining whether the Fresnel being examined is acceptable Focus the camera to 10 4 for viewing the chart a First view the Fresnel against the background presented in Section of the chart Note whether the defects dirt scratches digs etc are in the A or B aera of the Fresnel b Nest compare any boot or mirror marks on the Fresnel with the marks shown in Section II of the chart If the mark exceeds that shown on the chart the Fresnel is not acceptable c Viewthe Frenel screen againstthe background of Section II on the chart The conditions shown on the chart are the maximum acceptable limits for Fresnel defects If the Fresnel being examined has defects which go beyond those shown on the chart reject the Fresnel Note that an illustrated listing on the chart is available for comparison to Fresnel which have only one or two blemishes d Examine any shading on the Fresnel against the limits shown in Section IV of the chart If t
64. readings must agree with specifications 11 Recycle the camera by removing it from the horn and then reinstalling it on the horn This is necessary for the next portion of the testing c Flash Circuit and S9 Mode Test 1 Set 5 0 volts on the tester voltmeter Set light level at 6 25 and close S2 2 Press the exposure button The numbere one READY lamp will go off and the number the number one FLASH indicator lamp will light 3 Press and release the exposure button four more times The READY lamps should go off and the FLASH indicator lamps should light in numerical sequence each time hte exposure button is pressed 4 Press and release the RESET button on the flash simulator assembly 5 Press and release the exposure button five more times The READY and FLASH indicator lamps should sequence as in step 3 6 On the flash simulator assembly press and release the RESET button 7 Press the exposure button actuator The number one READY indicator lamp should remain lighted and the number one FLASH indicator should not light Checks S9 NOTE The toggle switches on the flash simulator assembly can be used to simulate normal or used flash lamps By settinag the individual switches partially exhausted or deflective flash bars can be simulated d Follow Focus Test The follow focus test is used to determine how well the shutter blade opening follows the focusing of the lens in flash mode operation The APERT
65. s the power supply mete is not adequate to set the voltage Use an external meter VOM or VTVM to make this setting INFINITY LENS Figure 3 2 SX 70 Collimator ADDED TARGET e zones Figure 3 3 Location of new collimator target d Set the power supply to the AMPS position b Remove front cover from camera c Insert the pack simulator into the camera as you would a film pack with the contact down Close the camera S7 switch using the actuator 2 Collimator Figure 3 2 When performing several of the Comprehensive Tester checks a requirement of the test is that the camera lens be correctly collimated For this reason and because the lens can be checked simply and rapidly the collimation checks should be done before Comprehensive Tester checks Collimation for the SX 70 camera is done on the special collimator as indicated below a Collimation of the Split System Image Viewing NOTE If the collimator is not available set the focus wheel to infinity and look at a scene at least 200 feet away Observe that the focus is sharp within a tolerance of 1 tooth to 2 teeth beyond the infinity setting of the focus wheel NOTE If an early vintage collimator is being used a new adhesive backed label must be added to the target in the position show in Figure 3 3 1 Remove the camera front cover and load the camera onto the horn of the collimator 321564 Figure 3 2 The collimator uses a rear illuminate
66. s 0 Figure 1 9 Inserting the flash bar 10 Closing the camera When through using camera it be can folded and latched in its closed configuration by pushing the erecting link When the camera is closed the interlock switch S6 is opened so that the battery is completely disconnect from the camera circuits The trim wheel the lighten darken adjustement associated with the photocell automatically returns to its normal position each time the camera is closed C SHUTTER DESCRIPTION AMBIENT LIGHT MODE The shutter employed in the SX 70 camera is unique No direct comparisons should be drawn between the manner in which it functions and the function of other Polaroid electronic shutters No manually adjustable or fixed aperture is employed When a picture is taken two shutter blades with specially shaped cutouts open the lens from a totally closed position to a suitable aperture The two blades then reverse direction and again shut off the optical path These same two blades also contain a similar although differently shaped pair of cutouts that open and close the light path to the photocell in like manner In the following description the functions of photocell cutouts is deferred until the action of the shutter cutouts is explained although in operation the two functions are interdependent When the camera is open for viewing but before the release button is pressed solenoid 1 is deenergized and the shutter blades ar
67. seconds delay which allows the Fresnel carrier to come to rest after its travel This eliminates bouncing caused by the sudden stop of the carrier on the mirror cover At the end of the Y delay power is removed from solenoid 1 allowing the spring to open the shutter for exposure and moving S4 from CB to CA position When the proper exposure level is reached the photocell trips the Schmitt Trigger S T in the ECM which sends full power to solenoid 1 This closes the blades and tranfers S4 from CA to CB As before closing CB cuts solenoid 1 s power from full to low sufficient to hold the blades closed closing CB also signals the electronics to start the motor The motor starts the gear train again and this time the cams cause a series of actions at different position of gear train movement it starts the pick which pulls the film into the rollers one of which is attached to gear train it is this powered roller rotation that pulls the film through and out of the camera it stops the pick it pulls down the Fresnel carrier which in turn moves the counter to the next number it moves the recock ram closing S3 resetting it for the next cycle it retruns the pick it seats the Fresnel carrier so it is ready for the next cycle it moves the recock ram closing S5 which stops the motor and it stops the spred action When S5 closes it cuts power to the solenoid 1 the spring opens the shu
68. the comparison of a lenticular projection screen compared with a matte surface The ribbed surface of the lenticular screen narrows the angle of reflectance but A FRESNEL SCREEN WITH SPLIT IMAGE CENTER v CENTER OF OF SPLIT i FRESNEL i FRESNEL GAGDVES ENLARGED SIDE VIEW SPLIT IMAGE Figure 2 3 Fresnel screen increases the brilliance of the image within teh viewing aera In summary the Fresnel satisfies three conditons 1 it enhances focusing by distributing light rays evenly across the entire viewing aera 2 it guarantees proper focusing by nature of its acting as a ground glass thus insuring that the subject is in focus when the eye sees the image in focus on the screen 3 it acts as a reflecting surface to permit the eye to see the image through the viewfinder optics As show in Figures 2 3 Aand 2 3 B two types of fresnel screens are used Current types Figure 2 3 A have a split image circle cut into the center of the screen which makes focusing easier Specially oriented prisms within the circle split the image unless the camera is perfected focused Therefore a straight vertical line in the image aera would appear to be broken unless the subject is in focus To further ease focusing the image within the split circle appears brighter than the rest of the Fresnel image This is possible because the split circle is not coated in the same manner as the rest of the Fresnel This latter feature improv
69. tions is contained in section In that section detailed analysis of individual assemblies and electrical circuits was minimized so that emphasis could be placed on the intenelation ship of various functions In the following paragraphs the individual groups of components are described in greater detail The description are presented in the sequence in the commponents were mentioned in Section I B POWER SOURCE Power for the drive motor the shutter electronics and the flash array is supplied by a specially designed 6 volts battery incorporated in each 10 exposures film pack When the pack is inserted into the camera two contacts pads on the bottom surface of the pack engage two spring loaded contacts on the inner bottom surface of the camera bottom plate From these two points it is distributed to its destinations by the copper foil strips of a flex circuit on the outer surface of the bottom plate u FYE LENG WAFEA LENS ZM TEN f a 7 atl ee FIREG A YVIEWiNG MIRROR FAESNEL SCHEEN Figure 2 1 Viewfinder optics viewing The battery has adequate capacity to expose all 10 film frames with at least six months of expected shelf life C LENS The lens employed is a four element glass lens of f 8 aperture with a focal lenght of 115mm It has a focusing range of infinity down to 10 4 inches Focusing is accomplished by movement of the front element only Helical threads in the lens mount provide the l
70. tter blades and S4 is pushed from CB to CA The blades open only if the operator releases the red button The system is ready for a new exposure cycle Springs are used in three of the operations discussed above holds the shutter blades open filos the Fresnel carrier up and holds the pick at the rest position As indicated inserting a film pack causes automatic action This could of course be a partial pack the top of the sheet of film would be ejected as a dark slide and the counter would registrer 10 After the last actual sheet is used the camera would still function until O is reached If a flash bar were attached and an unused bulb was available after the last film sheet was used attempting to make another exposure would fire the flash The difference in the flash mode are inserting a flash bar closes S2 which activates solenoid 2 to move the interceptor into position This controls the shutter blades according to focusing the closer the subject the more light from the flash will bounce back Therefore the smaller the permitted aperture At the end of the Y delay a flash delay circuit is activated and when S4 switches from CB to CA Ca sends power to the flash circuit During the fixed flash delay the photocell and S T are operative so that if enough light energy is collected before the end of the flash delay the blades will be closed as in ambient picture However on newer cameras P
71. ure 1 13A When the flash delay period reaches completion the circuitry removes the holding current from solenoid 2 Since the solenoid is an electro mechanical device removing power from it causes a collapsing magnetic field which induces a fly back voltage This voltage pulse is fed to the flash circuitry which then applies the firing voltage across the flash lamp a2 OFEN JINTEACLFIOR CLADE SHOWN CLEAR WG Pil 5 Interceptor link Solenoid 2 S2 operation Solenoid de energized ae 57 CLOSED Y FLASHBAR 5 me SHORTING CONTACT SUL 2 ACIUATON LINK z PUL LED IN AGAINSI TIE wis INLET HCE FIOM m i 3 at INTERCEPTOR ee AGAINST MN J eee At Figure 1 13 B Interceptor link Solenoid 2 S2 operation Solenoid energized TANG OF APCOCK HAM z 55 CON TACT Be Lr o iY Ol i Er Figure 1 14 S5 being opened by the recock ram Gear train In cameras with P configuration or later shutter there is no ambient light measurement made If a flash bar is in the shutter socket a flash picture will result regardless of the ambient light level On early cameras an ambient light measurement is made during the flash delay period Since the photocell aperture is a part of the shutter blades the amount of reflected light reaching the cell will also be a function of focusing distance the shutter electronics delays firing the flash lamp until the shutter has opened to the aperture established by the f
72. urface damaged beyond cleaning Should any of these faults be evidenced replace the assembly NOTE On older cameras a coding system is used to match Fresnels and mirror covers When changing mirror cover and Fresnel assemblies correct color coding must be employed to prevent unacceptable tolerance buildup This is usually demonstrated by difficult cloding the camera etc The chart below shows the color codes to be used a red coded Fresnel goes with either a red yellow blue or white mirror cover not with a green mirror cover The choice should be the first in order of the chart Red first yellow second etc The color code is located on the mirror cover on the underside upper right hand corner viewed as if holding the camera to take pictures On the Fresnel assembly it is marked on the protective paper at the point where the adhesive seals the paper around the Fresnel COLOR CODES USED WHEN CHANGING aD AND MIRROR COVERS sa ae px x fx X X ee eeue x x lx creen x x x x Cese x x Newer cameras employ a universal Fresnel Mirror cover assembly No matching of coded parts is necessary Removal 1 Erect the camera to picture taking configuration 2 Open and remove the front cover 3 Remove the decorative leather covering from the bottom cover 4 Remove the four bottom cover retaining screws 5 In the following step the bottom cover will be removed To prevent damage to the
73. urs d The operators closes and latches the front cover S7 closes power is apllied and the camera eject the dark slide NOTE During this action and in certain other operations other switches actuate and functions occur but unless they contribute to the paticular camera function being described they are omitted from the discussion The counter indicates exposures 10 and opens S8 thereby showing that the camera is ready to take first picture e The operators aims focuses the lens and presses the red shutter release button S1 The ECM actuates solenoid 1 which closes the shutter blades Solenoid 1 transfers the S4 contacts from CA to CB which in turn switches the circuit from full solenoid power to holding current power down Closing contacts CB of switch S4 also starts the drive motor Opening S4 CA removes power from the FFA f As the gear train runs it mechanically releases the spring loaded Fresnel carrier so that it leaves the film plane and rises to its exposure position This is accomplished by the mirror release cam of the recock gear the recock ram falls off the recock cam allowing the ram to snap forward This allows the drive spring to raise the Fresnel assembly to the exposure mode The ram also moves away from S5 allowing S5 to open This action causes the ECM to dynamically brake the motor which will remain at the rest throughout the exposure segment of the cycle The S5 switch action also pr
74. utments 1 Loose Front Covers some cameras have been detected with loose front covers due to improper latching This problem occurs when the knife edge of the front cover latch is not firmly and or correctly seated in the latch retainer thereby causing excess play between the latch and retainer To resolve this problem perform the following procedures a Confirm that problem is not caused by loose screws on the spread system assembly by closing the front cover and while rocking it slightly observing for excessive play b Two vendors produce the spread system assembly bracket Figure 4 2 One vendor Ramcel makes the bracket with a retainer aera which is not bent The other vendor makes the bracket with a bent retainer aera Most of the loose front cover problems occur with the bent retainer aera Therefore a simple solution is to replace the front cover or a spread system sub assembly with one containing a Ramcel spread roller bracket However before doing this try the repair procedure called out in paragraph c below Do not scrap the original front cover since it is still usable on other cameras c Ifa Ramcel bracket front cover is not available use the following procedure to correct the loose front cover 1 Open the front cover 2 Remove the gear train cover 3 With the la tch depressed use needle nose pliers to bend the knife edge of the latch inboard away from the front cover slightly less th

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