[violini]

The new mirror motor cost me $24 from UScamera. The price is prohibitive for the obsolete film cameras. A working ZX series of camera would worth about $30. Does any one here know where to get this replacement motor directly from supplier in China?

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Last edited by violini; 12-30-2010 at 09:02 PM.

[AndrewG NY]

Agree that is fairly pricey except that if you just buy another body it will be in unknown condition and may still contain the plastic-geared original. The better MZ/ZX-3/5/5n/6/L are still worth more than that but agree that some of the lesser bodies might not be worth the effort.

[violini]

I acquired recently a very much used MZ-6. The previous owner told me that she never had any problem with the camera which was used in the dance studio. Upon opening the bottom plate, I found that the mirror motor already equipped with brass gear. This is a "made in Japan" version. There is no date stamped on the inside of the bottom plate. All the "Assembled in Philippines" versions have date inside the bottom plate. I have no idea when they started to use motor with brass gear.

[wlachan]

It slips because it splits. If you measure the plastic gear carefully, you will realise the diameter is actually bigger with the defective gear which can only mean it splits. What will happen is if you managed to fix it on the metal shaft w/o slipping, the mechanism will jam randomly because the gear gap along the crack is so slightly bigger which cannot be seen by naked eyes. It will happen cos I tried already.

[violini]

Thanks Alan. I pulled the gear out of the shaft and examined under x10 magnifier, indeed it was split. Therefore, I would not try to repair the broken gear.

I also want to mention it here, for replacing mirror motor in cameras which do not have DOF preview button, you don't need to remove flash board/capacitors.

[CRM-114]

Hi
this is what I just tried:
https://www.pentaxforums.com/forums/attachments/8-film-slrs-compact-film-cameras/82952d1297068356-mz5n-mirror-blocked-service-manual-imgp3207a.jpg

First, I have no association with this firm, I just post the reference as I think it will make it easier for others to order the gear.

The fit is firm on the shaft, but I would use some glue, like isocyanate or similar to make sure.

the 3mm width is the max they do, and this is just enough, but still about 0.9 less than the original, so some care in the final placement.

I have not installed it yet, so I don't know the final verdict, but the gear meshes perfectly with the original, so a good sign.

[violini]

That's interesting. If the diameters are the same (3.75mm), it should work. I would suggest that you install the motor in the gear box and use your finger to rotate the outer light gray gear. If it matches, it should rotate fairly easily and smoothly. As Alan mentioned above, the split plastic gear would jam even though the split opening was so small that you couldn't see with naked eye. The new motor costs $25. I already have my share of fixing MZ cameras for my own collection. If I can find the right brass gear for the old motor, it might be economically viable to fix the lesser models such as MZ-30 and 50; no one would pay $25 for these cameras in working condition. (I found from the above web site, the price for the gear is 4.48 EUR + shipping). By the way, I can't detect any magnetic field on the motor, indicating that it's a brushed type and therefore its longevity is in doubt.

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Last edited by violini; 02-14-2011 at 12:34 PM.

[CRM-114]

OK, so having found the replacement gear, the next trick was to install it.

I have once before replaced the whole motor in an MZ5n, and frankly, this was 'intense'. I figured there must be a simpler was. (No slur on the previous guides reproduced here, after all, that's what gave me the impetus to trial this - and it is the 'proper way to do this job).

I also took note of the comments on the cost effectiveness of repairing MZ50 and lesser MZ bodies against the cost of new motors - hence the sourcing of the pinion on its own.

What is to follow is a quick and dirty way of fixing this gear failure.

Technicians and sensitive souls avert your eyes

First remove only the minimum for access, that is the bottom cover, both side covers and the mount cover.

Then unscrew the metal plate at the base, and swing out of the way. I found turning it 'clockwise' and hanging over the lens mount the best position - there is a ribbon connector that prevents total removal, so rather than trying to 'play' with it and break it I just opted for access clearance.

Remove white gear from the base - this will allow a better angle for a screwdriver to loosen one of the gearbox mounting screws.

Loosen the other gearbox mounting screw (near mount release).

You should now have enough slack in the gearbox plate to ease it apart. I restrained it 'open' by jamming a screwdriver in the gap - see photo.

You now have enough clearance to slide the split pinion from the motor shaft.

Insert new pinion with tweezers, making sure you clear the 'green' gear - it may foul the approach and not allow a perpendicular alignment of the pinion, and make it impossible to put on.

Once pinion is located on shaft, remove screwdriver holding gearbox open, this will provide tension to hold everything in place whilst you tighten the gearbox screws - make sure the pinion and grey gear wheel are meshed as you close up the gap - rotate with finger.

As you are closing up the gearbox, slide pinion on motor shaft - optionally, I put a tiny drop of isocyanate glue on the shaft - this is up to you, but be careful.

The rest as they say, is a reverse of earlier process..







I've put a roll of superia in it, and will post results

[noahsark6454]

so would you think or know if it would posible work for a SF1/SFX?

[CRM-114]

OK, got the film back from the minilab.

Everything is fine, took some shots in Av, Program and with flash. All came out fine, so there are no problems with the synch of the mirror or the aperture indexing.

It would appear this is a quick,easy and effective fix for what is arguably the achille's heel of those fine cameras. ;-)

[ysmin7]

Hi, I have a MZ-5 camera and it has same problem.

So, I tried to repair the camera, myself. But I can't reach the mirror box.
I disassembled my camera. Its top, bottom and grip cover was taken off.
Also, desoldered the flash board's wires. It's all. I can't advance anymore.

Who has the repair manual for MZ-5 ?

MZ-5 and MZ-5N are slightly different from LCD assembly.

Anyone help me, please.

Thanks.

[violini]

Since I've done 7 already, I can answer your question from memory. Un-solder the wires from flash board: black, brown, blue, and green; on the flexible board: white, green; purple, black, red, and yellow; on the battery contact: 2 black, one red, battery negative contact to flex. board, and pin to flex. board (this pin is connected to the battery pack). Remove the only screw at back edge near pano. switch; un-solder the 2 posts right beside it; 4 pillars connecting flex. to flash board. Then you can lift up the flex. board. The circuit board is double-face taped on the prism housing, carefully ply it loose on the right side. Since MZ-5 does not have DOF pre-view button, you don't need to remove the flash board/capacitors (don't need to unsolder the red wire as shown in Bob Bimon's post. The red wire is long enough, you can let it hang on to it even if you want to remove the flash board). For MZ-5N, remove 2 screws on flash board and the glue between small capacitor and DOF switch; lift up flash board. Remove the screw on DOF switch. Remove eye-piece, then 2 screws and 2 more on the other side (see Bob's post. ) Un-solder the black wire at lens mount. Then lift up the mirror box a little, more on the gear box/ motor side till you can reach the lower screw. There is a plastic lever extending about 5mm below the gear box to couple with shutter box. Lift up the mirror box until this lever is above the shutter box. Remove 4 screws and open the gear box. If mirror is not at "up" position, rotate the protruding light gray gear (push it downward) till mirror flip up. The split gear would jam, so you push the motor slightly away to prevent jam. Look from the lens mount, the mirror should be fully up and press on the bumper foam; there is an opening between mirror chamber and gear box, the metal slider which control the diaphragm should be at the top edge. If this is not at the top edge, you can't open the gear box cover, if you do, the yellow gear and 2 components behind the gear would come out and you'll have more work to do to re-assemble. The green (with 3 electric contacts) gear and yellow gear are synchronized by matching the holes at the rim. Before tightening the 4 screws of the gear box, rotate the light gray gear with finger. The motor is precious metal brushed, no load speed is 15K rpm. When you look at motor from gear side, it rotate clockwise; so I push the gray gear down with my thumb till mirror comes down, and the slider to couple with lens aperture lever is at mid point (i.e. lens aperture is fully open). Also before tightening the mirror box screws under the eyepiece, make sure the pano. lever also engage between the 2 dots on the side of prism housing. If this is not done correctly, the shutter would be jammed. The pano. lever operates the screen at the shutter and the screen in the prism housing. The whole process of replacing the motor takes about 2 hours. I tape the screws on a sheet of paper and write down where they come from so I can put them back to the original hole. I would like to add the following remarks: (1) The circuit board layouts of MZ-5, 6, and 7 are different from MZ-50. On MZ-6 and 7, there are no white and green wires to un-solder. (2) There is no need to disconnect the red wire on flash board. The wire is long enough to let it hang on to it. (3) On models which do not have DOF button, do not remove flash board/capacitor. (4) On MZ-6 and 7, the screw under PENTAX logo is hidden by the pop-up flash (which is controlled by the solenoid). You will have to temporarily install batteries, turn on the power, press black button and quickly turn off power. Even within a short time when the flash is popped up, the capacitors would be charged to 240 volts. After removing the screw, you can either leave the camera for a few days or lift up the top cover to discharge the capacitors. Use a 10 k Ohm resistor between blue and green wires for a few minutes till voltage drops to zero. Be very careful, the two terminals are very close together.

I've never owned any film camera before, therefore, film SLRs are novelty to me. I started to collect these people's thrown away old junk since last summer and have restored quite a few so far.

[ysmin7]

Hi, Violini. Thanks a lot for your kind explanation. I'd like to try again like your advice tonight. Thank you !

[violini]

PM me if you encounter any problem. Also read the camera review of MZ-5N I wrote.

[ysmin7]

Thanks, Violini. As your coments, I successed to disassemble the mirrobox.
Thank you.

But, unfortunately I can't solve my problem.
I'm faced with two problems utill now.

One is the original reason why I disassemble my MZ-5.
I don't know what is wrong. My motor's gear has a good condition. My case is slightly difference with others. So, I'll attach a picture of my gear assembly tonight. If you don't mind, let me know what is different from normal state.

Another was happened last night when I opened gear box cover. As your caution, the green(with electric contacts) and yellow gear came out. It's my mistake. Maybe I can set them to original position through a trial.
I believe it. ㅠㅠ

I need your help to solve this.

With best regards.