[FIX] Pentax 6x7 Mirror stuck and shutter open on slow shutter speeds

Discussion in 'Medium Format' started by unaval, May 8, 2019.

  1. Yesterday i found out that my Pentax 6x7 got some problems with slow shutter speeds from 1/125 and over, the shutter and the mirror stucks open forever.
    Like this:
    [​IMG]

    So i found a not so well explained solution online and this is my guide:

    1- Gently remove the leather from the left side (the side with the 6x7 print)


    2- Uscrew the 2 circled screws DO NOT UNSCREW THE THIRD.
    [​IMG]


    3- Unscrew the two circled screws inside the focusing screen zone
    [​IMG]

    4-Gently remove the piece by pushing it up and forward
    [​IMG]

    5- Unscrew the two screws
    [​IMG]

    6- Remove the piece
    [​IMG]


    7- Cock the shutter, remove the battery and shot to open the contact of the magnet and clean it easier.

    8- Clean the contacts with a small tissue paper wet with some contact cleaning detergent sticked to a thin screwdriver to reach every zone.
    [​IMG]

    9- Test

    10- Close everything

    11- Stick back the leather


    This would solve your problem, hope that helps!
     
  2. Silent Street

    Silent Street Silent Street Photography AUS

    This is really only a temporary fix. This does not solve the problem where age and wear are very usually the problem that can only really be remedied with full replacement of the parts giving trouble. This is particularly true with the very old Pentax 6x7 camera from c. 1969 which have seen heavy professional use in the distant past and must be expected to develop age-related faults over time. A more reliable fix is usually done by taking like-parts from another body (with such parts extensively cleaned and tested) and assembled. This however introduces a continuous cycle of redundancy and reliability because mint/new parts have long ceased to be available.

    Shutter speed anomalies can also be related to the switch board under the shutter speed dial e.g. dirt or the accumulation of corrosion (very common!). Remedial action is disassembly and thorough cleaning with an electronic solvent.

    FYI, never store any of the Pentax 6x7 or 67 cameras with the shutter speed on any marked speed: store it on B only. Similarly, the camera should not be left over a long period of time in a cocked state, as this too will effect shutter accuracy.
     
    unaval likes this.
  3. In my occasion all the circuits were clean and only the magnet was the reason of this issue, i also checked the speed dial because i thought it was the problem and all was in order and clean!
    I think that also cla help to keep the camera perfect in the time!

    didn't know about the B pose, i'm gonna do it!
    Thank you!
     
  4. My camera has the same problem. I agree that its a temp fix, as it worked for me for about 3 months, then it came back again. sent my camera to a famous pentax repair center. They told me after 3 months of looking, that there are no longer parts for the fix, hence they cant fix the camera. Im now in the process of looking for a spare camera to use for parts. sad news, but ne careful with you 67's out there
     
  5. Silent Street

    Silent Street Silent Street Photography AUS

    Parts ceased to be available in 1994, and residual inventory was long gone by 1998, so yes, scavenging parts from a like-camera is the only way to go.
    B (Bulb) is a "dead zone" for the Pentax 6x7 / 67 camera. When Bulb is in actual use, that is when the camera is draining power from the battery (a modification exists to enable either/both cameras to be operated independent of a battery so it can be used for astrophotography over very long periods of time).

    In places on the internet I have read of people picking up the Pentax 6x7 / 67 and dropping it onto a hard surface, several times, and then declaring "it's fixed now!" regarding the sticky mirror solenoid. I guess every village has an idiot...o_O
     

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