[butangmucat]

Hello,

My I was using MZ-M in continuous drive and with a fresh roll film on frame 1. After firing the shutter for frame 1, the mirror returned, but the camera immediately rewinded the film. I later tried another roll, and the camera rewinded it right after it's loaded. Upon half press the shutter without film, the camera seems to make some motor noise, but I can't release the shutter. Is this the plastic gear syndrome (if it is, it can be repaired relatively cheaply here in China)?

Sincerely

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[Steve Beswick]

Is the mirror stuck in the up position? That's usually a strong indication it's the gear, but sometimes the gear can fail and the mirror won't get stuck up. The real test is to push the shutter with the lens off. If the mirror doesn't move, it's the plastic gear.

[butangmucat]

Is the mirror stuck in the up position? That's usually a strong indication it's the gear, but sometimes the gear can fail and the mirror won't get stuck up. The real test is to push the shutter with the lens off. If the mirror doesn't move, it's the plastic gear.

The mirror won't move (in the down position), and the shutter won't cock/release.

Sincerely

P.S. the shutter was closed when the film was unloaded. Does this mean that the actual exposure of the 1st frame went without problems?

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[Not a Number]

Sounds like the gear problem. Where the cycle gets stuck depends on in which sequence that the gear started to slip. The most common failure is with the mirror up. The motor running constantly is a good indication as the gear just slips on the shaft without doing any work.

The problem with sending it out for repairs is the availability of parts. In the US the replacement motor with metal gear is no longer available. You can buy a compatible gear and any competent camera repair shop could replace it for you.

kkpmo - Zahnrad / Trieb M0.25 / 13 Zähne

Change the options to 1.5mm shaft opening, 2.0 mm width and material to brass. Or find some other source or someone who can machine the gear from the above specifications.

[butangmucat]

Sounds like the gear problem. Where the cycle gets stuck depends on in which sequence that the gear started to slip. The most common failure is with the mirror up. The motor running constantly is a good indication as the gear just slips on the shaft without doing any work.

The problem with sending it out for repairs is the availability of parts. In the US the replacement motor with metal gear is no longer available. You can buy a compatible gear and any competent camera repair shop could replace it for you.

kkpmo - Zahnrad / Trieb M0.25 / 13 Zähne

Change the options to 1.5mm shaft opening, 2.0 mm width and material to brass. Or find some other source or someone who can machine the gear from the above specifications.

For some reason there are still some shops here in China that has the right metal gear (either recycled, original, or just OEM compatible parts). I sent mine out to a guy who charged 200 RMB for the gear replacement and a clean on the viewfinder focusing screen (the previous owner didn't keep it clean), that is around 30 USD, just FYI.

P.S. They will usually keep the motor intact, but just replace the broken gear.

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[Ditechspain]

I’m trying to get back to film cameras after some years of never clicking with my K7 dslr.
My MZ-5 databack has had the seized mirror for some years. When I dig it out from wherever I’ve put it in the meantime I’m going to try replacing the gear. There’s also an MZ-5n in the family so it’s probably worth learning.
However as the problem has destroyed the value of these cameras I wondered about buying one with the factory-uprated gear/motor. Does anyone know from which serial no this applies?

[Steve Beswick]

I’m trying to get back to film cameras after some years of never clicking with my K7 dslr.
My MZ-5 databack has had the seized mirror for some years. When I dig it out from wherever I’ve put it in the meantime I’m going to try replacing the gear. There’s also an MZ-5n in the family so it’s probably worth learning.
However as the problem has destroyed the value of these cameras I wondered about buying one with the factory-uprated gear/motor. Does anyone know from which serial no this applies?

This one of those “I heard it form someone who heard it form someone” things, so take it with a huge grain of salt:

Around 2003, Anahi Pentax was bought/transformed into/was taken over by (I don’t know which it is) PENTAX Corporation. Right about that time, production switched to metal gears. So supposedly if you get one that says PENTAX Corporation on the bottom you are good to go.

Again, this is just something I heard from someone, and I don’t really know.

[Not a Number]

There’s also an MZ-5n in the family so it’s probably worth learning.
However as the problem has destroyed the value of these cameras I wondered about buying one with the factory-uprated gear/motor. Does anyone know from which serial no this applies?

It is unknown if the MZ-5n ever came equipped from the factory with the metal gear. The MZ-S is a different story. See the following thread beginning from the post linked below:
The real truth on the MZ-S mirror motor gear? - Page 3 - PentaxForums.com

[Ditechspain]

Thanks for that. I posted this elsewhere but could the metal gear be at all linked t o the move of production to the Philippines which occurred before the name change. Moving the production line would be a convenient time. But after 20 years there’s probably no way of finding out without Ricoh checking if the records still exist buried in a cellar somewhere. I’ve just picked up a mint working 5n with a serial no starting with 9. But it’s hard to find any evidence it’s ever been used.

Fingers crossed.

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