[vandergus]

I don’t know if this will be of interest to anyone but after the demise of my Pentax MZ-5 I decided to take it apart (somewhat brutally) for what useful spares I could salvage, screws,springs etc. and no, I was not going to attempt to repair the broken cog problem, in fact I couldn’t even identify which one caused the problem in the first place! However, two things leapt out at me.

Firstly, the number of plastic cogs, I counted at least 23.

Secondly and most most surprisingly, I found that the ‘pentaprism’ was made from three mirrors sat on top of the focussing screen - very similar to the old Mamiya ‘Porroflex’finder for it’s 6x6 TLR cameras.

This method of construction seems to typify how products are ‘built down’ to a price range and possibly a lifespan. Based on internet posts, this range of Pentax cameras werenot very long-lived before the dreaded ‘cog’ problem reared it head.

That's not an MZ-5? The top plate looks like one of the MZ line with a PASM dial and a larger LCD. Those cameras did have a pentamirror viewfinder. The MZ-5/5n/3 have a true pentaprism and are supposed to be a bit brighter.

But yeah, they both have a ton of plastic parts. It's kind of funny. People seem to really shy away from electronic cameras because the electronics are perceived as less reliable than mechanical systems. But it's usually the mechanical bits of these cameras that fail. The parts that have been down graded to plastic when they used to be metal. The electronics themselves are very reliable. It's very unusual to have a chip or transistor just stop working. So it's not the electrification that made these cameras less robust and less repairable. It's all the cheap plastic parts.

[steephill]

Mz-50?

[vandergus]

Mz-50?

That would make the most sense based some of the other features you can see in the photo. Plastic lens mount, pop-up flash release, notch in the back of the top plate. Could be a MZ-10 but probably a MZ-50. Maybe with the '0' rubbed off

[Old Keith]

Apologies to all and thanks for pointing out the error of my ways. I seem to have had a total brain freeze throughout this episode. When the MZ-5 died I put it in my 'busted for spares' box alongside a couple of busted MX-50's. It is now obvious that when I grabbed the MZ-5 to strip it down I inadvertently picked up an MZ-50 by mistake because the MZ-5 is still in the spares box together with the remaining MZ-50. May I plead temporary insanity caused by camera bereavement.

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[Bonner04]

For the MZ-S the bodies with a s/n of 5xxxxxx are supposed to have the brass gears and not the plastic like in the earlier 4xxxxxx s/n range.

I'd look for in the the higher s/n range.

Phil.

Now I know and have to take a look at my MZ-S's. Thanks!

[Kevin Pritchard]

The dreaded day has arrived and my Pentax MZ-5 is now suffering from the infamous mirror return problem. It started with a slightly longer reset after an exposure and quickly progressed to the mirror not resetting every third ot fourth frame. It occasionally stays up and will only release when the camera is switched off. I understand this is caused by a plastic cog splitting on the mirror drive motor, the repair of which is way beyond my capabilities so it looks as though it will end up on the well know auction sitte for sale as 'Nor Working - for Spares or Repair'.

Whilst I love my SV and MX, sometimes I need autofocus to help out with my ageing eyesight so I need to find a cheap alternative here in the UK - recommendations welcome.

You could get it fixed, e.g. by <service@asahiphoto.co.uk>
Peter Emanuel there told me the cog is almost the only thing that ever goes wrong, and he has a supply of new cogs that he has had manufactured from better material.
Of course it might be cheaper to buy a replacement old one, or two, and treat them as semi-disposables.
I got mine precisely because my old eyes struggle with manual focus on ME Super or Spotmatic (I can do it on LX with its excellent diopter adjustment and bright VF). I really like the MZ-5 - though, like everything, it has quirks (the dim, tiny viewfinder info compared to K, M or L cameras).
Kevin

---------- Post added 12-11-22 at 08:25 AM ----------

You could get it fixed, e.g. by <service@asahiphoto.co.uk>
Peter Emanuel there told me the cog is almost the only thing that ever goes wrong, and he has a supply of new cogs that he has had manufactured from better material.
Of course it might be cheaper to buy a replacement old one, or two, and treat them as semi-disposables.
I got mine precisely because my old eyes struggle with manual focus on ME Super or Spotmatic (I can do it on LX with its excellent diopter adjustment and bright VF). I really like the MZ-5 - though, like everything, it has quirks (the dim, tiny viewfinder info compared to K, M or L cameras).
Kevin

[mlag]

That's not an MZ-5? The top plate looks like one of the MZ line with a PASM dial and a larger LCD. Those cameras did have a pentamirror viewfinder. The MZ-5/5n/3 have a true pentaprism and are supposed to be a bit brighter.

But yeah, they both have a ton of plastic parts. It's kind of funny. People seem to really shy away from electronic cameras because the electronics are perceived as less reliable than mechanical systems. But it's usually the mechanical bits of these cameras that fail. The parts that have been down graded to plastic when they used to be metal. The electronics themselves are very reliable. It's very unusual to have a chip or transistor just stop working. So it's not the electrification that made these cameras less robust and less repairable. It's all the cheap plastic parts.

They are also incredibly light compared to a DSLR.
I guess it is one reason why I like my MZ-7 .

[vandergus]

They are also incredibly light compared to a DSLR.
I guess it is one reason why I like my MZ-7 .

Oh absolutely. I used to have a Nikon N90 as my "modern" film camera but it was too big and heavy for my liking. I went searching for a smaller camera that still had a lot of features and a good control scheme and I landed on the MZ-3. I love it. Fantastic camera. I knew about the reliability problems going in but decided to learn how to fix them. Now fixing broken MZ's is my new hobby

[UncleVanya]

They are also incredibly light compared to a DSLR.
I guess it is one reason why I like my MZ-7 .

Lol. My first Nikon SLR was a mere 750g (ft3) and my second was 830g (F2a).

[Old Keith]

You could get it fixed, e.g. by <service@asahiphoto.co.uk>
Peter Emanuel there told me the cog is almost the only thing that ever goes wrong, and he has a supply of new cogs that he has had manufactured from better material.
Of course it might be cheaper to buy a replacement old one, or two, and treat them as semi-disposables.

Kevin

Thanks for the info Kevin, I wasn't aware there was anyone left who would touch these cameras.

[Jonathan Mac]

Get a Z1 or, if you can't find one, an SFXn is essentially a clunkier version. Both far more reliable than an MZ camera.

[Murdoko]

MZ-6 bodies with "Pentax Corporation" (made 2002 and later) instead of "Asahi Opt. Co. Ltd" and serial number that starts with 5 or 6 are likely to have brass gears.

Another tip is to get a split focusing screen from a MZ-M which fits the MZ-6.

Now, watch the MZ-6 prices go up..

[TwoUptons]

So is there a way to see the gear without taking off the front plate?

-Eric

[vandergus]

So is there a way to see the gear without taking off the front plate?

-Eric

There's not really a good way to do it without at least some disassembly. But if take the bottom plate off (just remove a few screws) you can usually get a peak. Shine a flashlight in there and you should be able to see a glint of brass if it is present. If you don't see any sparkle, it's probably a black plastic gear.

[Murdoko]

There's not really a good way to do it without at least some disassembly. But if take the bottom plate off (just remove a few screws) you can usually get a peak. Shine a flashlight in there and you should be able to see a glint of brass if it is present. If you don't see any sparkle, it's probably a black plastic gear.

+1 on this. If it sparkles, then you have a brass cog. Easy enough to just take the bottom plate off.. I think it is just 6 or 7 screws. Please keep it mind that they are different sizes so make sure you note where you take them off.

However, it is easy enough to take the front plate off too. Just a bunch more screws First, remove the plate around the mount (this needs a bit of force because the plastic is really flush against the mount. Then, take the left front plate off (if viewing it from the front). You need to remove the back cover for this as there are two screws hidden next to the hinge.

I read a couple years ago that there's a way to replace the cog just by loosening and rotating, but not completely removing the bottom plate, and loosening a few screws of the motor to get a tight access to the cog. I attempted this method ages ago but failed. Have you attempted this by any chance?