PRODUCT No.23900 ASAHI PENTAX SERVICE MANUAL ENGLISH 23900 Disassembly Procedure ME 1. Self-timer charge lever assembly (0-A118)--Self-timer screw left-handed (A122) -- 231K-H50 2. Body Covering, left and right (A19, A20) 3. Install self-timer lever assembly (0-A118) temporarily. 4. Bottom cover assembly (A400) -- CSS 1.7 x 2.8 x 3 Connector seat (A23), R button (C117) 5. Winding lever assembly (0-C69) Cover screw (C139) -- 23600K-C135-A (left handed) Winding lever nut (C8) -- 23600K-C134-A2 Cover ring (A321) 6. Shutter dial Shutter dial at AUTO Loosen set screw (A319) -- Shutter dial (A316) Release pin (A313) -- Release button (A317) 7. Rewinding knob R Rewinding knob assembly (0-D6) -- Nut (D15) - Washer (D21) - ASA dial assembly (0-D11-01) 23600k-D4-A2 8. Top cover assembly (A300) - 4 screws - cover frame (A131) 9. Unsolder 12 lead wires and one contact piece Take out lead wires from cord holder Lead wire No. 21 (K100), No. 24 (T100), No. 22 and No. 23 (T100), No. 19 and No. 20 (N4), No. 15, No. 16, No. 17, No. 18 and one Contact piece (A129), No. 26 and No. 27 (0-A21). 10. ASA volume assembly (R100) - Top cover screw (A16) - CNL-d 1.7 x 2.5 11. Hot shoe contact piece (N4) 12. P.C. board retainer (I1) - W14 13. P.C. board retainer plate (N5) - T-CNS 1.7 x 5 14. LED retainer screw - CNL-D 1.4 x 2 - W31 15. P.C. board assembly (T100) 16. Front board and mirror housing Cocking the shutter Removing 5 screws - W14 Shutter light seal cover (A8) 17. Bulb actuator plate (A504) - CNL-D 1.4 x 2 18. Cocked indicator assembly (0-C23) SW actuator lever shaft (C49) 23900 Page 1 of 15 19. Counter dial Back cover open Counter dial spring (C57) - Counter retainer plate (C25), Counter dial assembly (0-C34) Come off transporting claw spring (C65) Remove (C146) (C53) and CNS 1.7 x 3 Winding seat assembly (0-C2) - (0-C5) - (C7) 20. Shutter block (S000) - CNL-D 1.7 x 3 x 3 21. Bottom release assembly (0-C147) Winding up little from bottom part with tool (23900K-C207-A) To remove retainer screws of (0-C147). 22. Release plate assembly (A500) Guide screw (A507) - Release plate restitution spring (A510). When removing (A500), detach hook lever (C108) from (A500) 23. Shutter charge lever assembly (0-C129) Loosening joint (C207) with tool (23900K-C207-A), remove (0-C129) and (C144). Fasten joint (C207) again. 24. Winding guide plate assembly (0-C102) 25. R lever assembly (0-C105) LW-13 - (0-C105) - (C126) (C145) - LW13 - (C144) - (C107) - (C130) - W14 - (C108) - W8 - (C125) (C207) - (0-C106) - (0-C12). 26. Back cover assembly (0-C26) 27. Winding stopper assembly (0-C26) 28. Winding shaft assembly (0-C22) - Main gear (C30) 29. Sprocket shaft pin (C40) - Loosening set T 1.7 x 1.6 30. Top mec. Plate assembly (0-C1) - (C146) x 2 - CSS 1.7 x 3 31. Spool cam assembly (0-C202) and spool assembly (0-C204) - W17 (t=0.2mm) 23900 Page 2 of 15 Assembly Procedure 1. Spool assembly (0-C204) and spool cam assembly (0-C202) W17 (t=0.2mm) 2. Top mec. Plate assembly (0-C1) Pulling back transport indicator 3. Sprocket shaft pin (C40) Apply screw lock on Set T 1.7 x 1.6 4. Winding shaft assembly (0-C22) - Main gear (C30) 5. Winding stopper assembly (0-C26) 6. Winding spring assembly (0-C12) Proper tension of the spring is shown in figure. After installing (0-C12), install (0-C106) and (C207) temporarily. - 23900K-C207-A 7. Perforation adjustment - Tool 23102-C57-A Same adjustment with K2 camera. Choosing proper 2nd gear (C31). 8. Bottom mechanism a) (C125) - W8 (t=0.1) - Winding hook lever (C108) - W14 (t=0.05, 0.1) (C130) - Winding lever ratchet (C107) - LW13 - (C145) b) (C126) - R lever assembly (0-C105) - LW13 c) Winding guide plate assembly (0-C102) - (C146) - CSS 1.7 x 2.5 - CNS 1.7 x 3 d) Shutter charge lever assembly (0-C129) Loosening (C207) - (C144) - (0-C129) - fastening (C207) When fastening (C207), winding shaft should be in the wound position, at the same time, mirror charge lever (0-C102) should be moved to a correct position 9. Shutter release plate Release plate restitution spring (A510) (Take care to install spring in correct direction) Release plate assembly (A5000 (Take care not to bend winding hook lever (C108).) Guide screw (A507), connection spring (A511) (Engaging (A510) to (A500).) 10. Bottom release assembly (0-C147) - CNM 1.7 x 2.2, CNM 1.7 x 2.8 Winding shutter a little 23900 Page 3 of 15 11. Shutter block (E000) - CNL-D 1.7 x 3 x3 Light seal plate (A8) 12. Bulb actuator plate (A504) Temporary installation - CNL-D 1.4 x 2 13. Back cover assembly (A200) 14. Winding seat assembly (0-C2) - (C53), (C146), CNS 1.7 x 3 Install (0-C2) with back cover open Winding lever click cam assembly (0-C5) Winding lever friction spring (C7) Engage transporting claw spring (C65) 15. Counter transporting adjustment a) Check the function of counter dial stopper lever (C4) and transporting claw assembly (C18). b) If the vertical black lever of (0-C26) is bent forward, bend it straight. c) Adjust the counter transporting function using the temporary counter transporting gear (C34). When back cover is closed, receiving claw (C16) and transporting claw (C18) should be engaged to the first tooth of (C34) simultaneously with enough gearing portion. Bend the tip of the claw which couples with the gear (C34), If not enough gearing portion. When back cover is opened, claw tip of (C16) must detach from the gear (C34) with a clearance of about 0.5mm. If there is not enough clearance, bend the other end of (C16) opposite from the claw as shown in the figure. 16. Counter dial Counter dial assembly (0-C34) Counter dial spring (C57) Counter retainer plate (C25) (C25) is installed in left side gutter as shown in figure. Give the spring (C57) 1/2 or 3/4 turns of tension. 17. Bulb off adjustment (Winding lever is at pre-advance position.) After releasing the first curtain, adjust "B" off position with eccentric screw riveted on bulb actuator plate (A504). When shutter rod comes back, 0.2mm clearance is necessary after releasing the 2nd curtain. 23900 Page 4 of 15 18. Cocked shutter assembly (0-C23) - SW actuator lever shaft. 19. Main SW adjustment = (I200) When shutter actuator plate is held in "ON" position, 0.2mm clearance is necessary between longer contact piece of main SW and insulation blue collar. To adjust the clearance, bend the shorter contact piece. When both contact pieces touch each other, and the shorter contact piece is pulled down, the longer one should be down also as the shorter one does. If there is not enough tension on the longer contact piece, it may show uneven shutter speed. When winding lever is at closed position, 0.2mm clearance is necessary between both contact pieces. 20. Front board and mirror housing When the above mentioned parts are installed, shutter block (E000) should be cocked but not charge mirror housing. Put on W14 (0.1mm) underneath front board and fasten it with (A132), pushing down left. Confirm the function of self-timer, shutter mechanism and mechanical back. 21. Parallax adjustment 22. P.C. board pattern assembly (T100) (I1) - CNL-D 1.7 x 2.5 - (N5) - T-CNS 1.7 x 5 - (N4) - (N6 x 2) 23. ASA volume assembly (R100) - (A16) - CNL-D 1.7 x 2.5 24. Soldering 13 lead wires 25. Bottom cover assembly (A400) - (A23) - (C117) 26. LED positioning adjustment 27. Temporary top cover and installing ASA dial assembly (0-D11-01) and winding lever temporarily. 28. a) Shutter speed adjustment - VR-A ASA 100, X1, f8, (KA-00-1A), 2.8V EV12 - 1/60 EV16 - 1/1000 EV8 - 1/4 23900 Page 5 of 15 b) LED indication adjustment High EV (EV12), EV16) Low EV (EV8) - VR-B VR-C c) Battery checker - VR-D 2.45V - Turning on and off (flickering) 2.55V - Turning on d) VR-E is prohibited to adjust 29. Counter indication (C15) - (A300) 30. Top cover (A131) - (A300) Set shutter dial at "B" Shutter restriction lever is set at left (viewing from back) Put on top cover softly and fix it turning shutter dial to AUTO position Four retainer screws Rewinding parts, shutter dial, winding lever, etc. 31. Shutter stroke adjustment a) Set shutter dial at "B" b) 0.2mm clearance is necessary after releasing shutter. Adjust the shutter stroke with eccentric screw. 32. X Synchronization with self-timer operation at "B" When camera is operated with self-timer operation at "B" position, exposure time should be adjusted around 11~13ms. To adjust the exposure time, bulb actuator plate (A504) should be moved up or down with eccentric screw. Also check shutter dial 100X with self-timer operation in the same manner. If camera is not adjusted as mentioned above, it is impossible to take pictures with complete synchronization with electronic flash, especially in the following combination such as shutter dial at 100X, winding lever at closed position and with self-timer operation. 33. Focusing 23900 Page 6 of 15 34. Body covering, self-timer lever assembly (0-A118) Self-timer screw (A122) - left-handed. 35. Disassembly of front board and mirror housing a) Remove self-timer (H000) b) Mirror release lever (0-A111) c) Mirror housing d) Connector (I100) - only loosening (I2) e) Unsolder 5 lead wires Purple 2, orange 2, black 1 36. SWg, SWm located underneath mirror housing SWg = Magnet switch SWm = Memory switch a) SWg - Spring tension adjustment 8~10g spring tension is desirable: Check with tension gauge. b) SWm adjustment Bend longer contact piece as shown in figure. Shorter contact piece should have proper tension. (Check the tension after charging the mirror housing.) c) SWg adjustment When mirror housing is charged, 0.2~0.3mm clearance is necessary between both contact pieces. Bend longer contact piece as shown in figure. 23900 Page 7 of 15 37. Adjustment of SWm and SWg Time lag sequence of SWm and SWg To check the time lag, an oscilloscope is necessary. The time lag is determined by the variation in voltage when SWm and SWg turn "ON" and "OFF". Here is one example for time lag check with a single-trace oscilloscope. Adapter should be made as shown below. Adapter is connected to mirror housing connector and oscilloscope. After charging the mirror housing and releasing it to put the mirror in the "up" state, time lag appears on the oscilloscope screen. The adjustment procedures can be referred to in item 36. 23900 Page 8 of 15 PENTAX ME Notes and Troubleshooting Tips FIGURES: Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. 1 2 3 4 5 6 7 8 9 Top cover removed Bottom cover removed Front of camera, wind side Front view, mirror box removed Bottom of mirror box Current style, mirror switches Circuit for testing mirror switches Wiring diagrams Modified bottom cover ADJUSTMENT LOCATIONS: Auto speeds Meter readout, high light Meter readout, low light Battery test Release overtravel Mechanical speed Travel time, 1st blade Travel time, 2nd blade Trigger switch (fast speed) Magnet switch A B C D E F G H I J Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. 1 1 1 1 3 4 4 4 4 5 ADJUSTMENT VALUES: Blade travel time: Flange-focal distance: Release overtravel: Mechanical speed: Battery test: Memory time lag: 6ms (20mm distance) 45.46mm (flange to film guide rails) 0.2mm additional travel of release slide after shutter releases 11ms to 13ms exposure time when operated with self-timer action at bulb setting Viewfinder LEDs to light steadily with 2.55V supplied and to flash on and off at 2.45V Magnet switch SWg to close 10ms after memory switch SWm opens 23900 Page 9 of 15 ADJUSTMENT SEQUENCE: 1. Auto speeds Variable resistor A set: ASA 100, X1 compensation, f/8. With 2.8V supplied to the battery compartment, the shutter should deliver the following shutter speeds ath the indicated light levels: EV12 1/60 second EV16 1/1000 second EV8 1/4 second 2. Meter Readout EV 12 and 16 Adjust variable resistor B EV8 Adjust variable resistor C Later versions of the flex circuit board have only one meter readout adjustment, Fig. 8. 3. Battery test Adjust variable resistor D for proper operation. Later versions of the flex circuit do not have the batery test adjustment. It is then only necessary to make an operational check. AVOID DISTURBING: Variable resistor VR-E on the menory circuit board (not accessible until the flex circuit has been removed). In some versions of the flex circuit, VR-E is at the top of the camera. DISASSEMBLY HIGHLIGHTS: Control positions: Speed selector Film speed Auto Unimportant Location of left-hand threads: Winding lever cap screw Winding lever retaining nut Self-timer lever screw Sequence: 1. Bottom cover (Loose parts: cover for power winder terminals and rewind button) 2. Top cover (Remove black ring at top of speed selector; top cover screw is then accessible through hole in speed selector) 3. Unsolder film speed resistor wires (two yellow) from flex circuit and from diaphragm resistor (if you're just removing the flex circuit, unsolder only the film-speed resistor wire that connects to the flex circuit) 4. Film-speed resistor (not necessary if you're just removing the flex circuit) ...