Pentax 6X7 & 67: Mirror stuck repair

A common problem of old Pentax 6X7 and 67 cameras is that their mirror gets stuck in upper position after the shutter has fired and remained open. There are several reasons for the mirror to lock up all the way with the shutter open, but the most common one has to do with the shutter holding magnet. The core of the magnet gets magnetized and stops releasing the second curtain. Usually cleaning the magnet and electrical contacts solves the problem. So, let’s begin the repairs.

Repair

Attention! Do not attempt to repair your camera until you read this article till the end! Well, to get access to the magnet and electrical contacts, you need to remove a few covers from the camera body. First, you need to take out leatherette finishing which covers the screws. Next, let’s see a disassembling scheme on how to remove the covers. You can find it on the page 96 of the “Pentax 6X7 Service Manual” available here. See the image below for the details. I marked in red the parts that should be removed.

Mirror stuck repair. Pentax 67 side cover disassembling scheme

Scheme of disassembling to get access to the magnet and other electrical contacts

The original service manual available on the web is for earlier versions of the Pentax 6X7 camera with no mirror lockup unit. But the disassembling of Pentax 6X7 and 67 cameras does not differ significantly. However, there are some very important points.

  1. Note a screw highlighted with the green arrow. The former is not shown in the manual but is present in actual cameras. I’ve included it in the scheme.
  2. Screws highlighted with the red crosses should not be unscrewed. One of these screws fixes the spring of MLU lever. This spring prevents the lever from dangling. See the image below for the details — this screw should not be unscrewed!
Mirror stuck repair. Pentax 6X7 & 67 MLU side cover. Left image displays the screw itself. Right image displays the spring fixed by the screw

Pentax 6X7 & 67 MLU side cover

Ok, now we have got the access to the magnet and other electrical contacts. See the image below. The areas marked with the red arrows should be cleaned with special liquid electrical contact cleaner or absolute ethanol. To clean the magnet (marked with the left red arrow) you should cock the shutter, then take out the battery and press the shutter release button. The mirror will get raised by a half, releasing the lever above the magnet. This will allow you to clean this spot well.

Mirror stuck repair. Pentax 67 MLU mirror magnet. Spots marked with the red arrows should be cleaned with special contact cleaner liquid or just with absolute ethanol

Spots marked with the red arrows should be cleaned with special contact cleaner liquid or just with absolute ethanol

Now the cleaning is done. It’s time to check the camera. If the problem appeared during shooting on slow shutter speeds, then start testing it on the fastest shutter speeds and vice versa. Watch this video for more details of the process. Do not forget to select HD quality of the video.

Maintenance

In its operating manual Asahi recommends to check a camera’s performance at least once a year to maintain it in a good working condition. In my practice it should be checked more often and it rather depends on a camera’s condition.

For instance, I had a camera body which was heavily used by its previous owner, and its mirror got stuck every time it had not been in use for two months or even less. However, I’ve noticed that “dry fire” helps extend the period until the next mirror stuck.

I think the dirt resulting from gear friction near the magnet sticks to it tightly when a camera is not in use for a certain period of time. And the older your camera gets, the shorter this period becomes. Eventually, I disassembled my camera body and successfully repaired it. This experience enabled me to write this article. So, I think that it is a good practice to carry out a “dry fire” series if you don’t use your camera for at least two months.

P.S.

Ok, I hope that now your camera is again up and running! If not, there is one more trick which may be of help. When I started researching the web about this issue, I discovered that cleaning the contacts under the shutter speed dial could fix the problem for some people. Frankly speaking, it did not help me at all. Maybe, it works only for certain shutter speeds. But why not try it if the solution in this article did not help you. Good luck and keep snapping!

// Sasha Krasnov
Sunking 4LR44, Varta 4SR44, Kodak PX28 and 4pcs GP LR44

← Four LR44 button cells as replacement for PX28 battery

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Pentax 67 Macro Extension Tubes

11 Comments

  1. Dominik

    Thanks, this saved my beloved Pentax 67

  2. Derek Finlay

    Thanks mate ,It worked for the 6×7 I had that didnt work . I couldnt be happier ,Thanks Sasha

  3. Warren

    Very good article!

    You should do a thing about the contact on the other side of the mirror housing. They are the bits that turn on and off the meter from AUTO to MAN. Mis-alignment over time from the stationary contact, it bends from use or simply gets dirty. That would help some folks with mysterious meter issues that may work for MAN mode and not for AUTO mode.

  4. Michael

    Great guide and video. It worked for my Pentax 67 body that had the issue at slower speeds. Very little difference step 3 in red had one extra screw and i had to be careful that the spring for the meter prism lock didn’t leap out. the contacts to clean are in a little different spot but same area. One thing to add as well is some people have found cleaning the contact under the shutter speed dial some times have fixed this issue as well.

    Great guide thanks for tanking the time to post it.

    • Thank you, Michael! You are right, there is one more screw in the step #3, which is not displayed in the manual. It should be added to the scheme.

      I have two Pentax 67 bodies and both seem to have this problem: one of them plays up on slow shutter speeds and the other, on fast shutter speeds. The first solution I’ve discovered was cleaning contacts under the shutter speed dial. And it did help many people, but not in my case, unfortunately. Some time has passed and I forgot about this solution. Now you reminded me of it. Thank you for this.

      I think it is a good idea to add it to my text as an additional solution or, maybe, even create a separate article.

  5. Garyh

    Great detail of the beasty’s ‘innards’!
    In the Pentax 67 owner’s manual it is stated that leaving the selector on any speed for an extended period of time will cause the shutter speeds to become inaccurate. Ditto, it is also stated that if the shutter is cocked for an extended period of time, the same thing will happen. This has to do with the shutter/mirror solenoid? What constitutes an “extended period of time” is open to conjecture, but I suspect quite a few months of inactivity / shutter cocked, rather than transient use. It would seem reasonable that frequent “exercise” is the best prevention, followed by keeping the camera out of an environment where inside attack can occur e.g. shooting in salt spray at the beach, in a very dusty environment or in extreme heat.

    • Thank you, Garyh!

      Yes, you are right. I’ve just revised the manual. Sure, Asahi recommends to check a camera’s performance “at least once a year”. So, I suppose it refers to one year as “an extended period of time”. In my practice this period lasts much less than a year and depends on a camera’s condition. I had a camera body which was heavily used by its previous owner, and its mirror got stuck every time it had not been in use for two months or even less. But at the same time I’ve noticed that “dry fire” extends this period. I think the dirt resulting from gear friction near the magnet sticks to it tightly when a camera is not in use for a certain period of time. And the older your camera is, the shorter this period becomes. Anyway, I had to disassemble and clean it. I should include this info to the article’s “maintenance” section, it is a very important addition.

  6. zdenab2

    Hi from Czech
    Thank you for save my AP 6×7 first version.
    Sorry for my bad english.

  7. Hi Sasha, thanks for the instruction.
    At one point the winder stuck midway. I can’t figure out where the problem is. I cleaned the contacts first, did some tests and the winder stuck. I put a fresh battery in, no luck. Do you have a fix for this? Thanks!

    • Hi Darko

      It seems to be a problem in winder mechanism. It is very difficult to disassemble this part. I personally recommend to send for the repair service. It may be a problem in one of the gear but you don’t know which one should be replaced. To understand it you will need to disassemble a half of the camera. It is better way made by the specialist!

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