The real truth on the MZ-S mirror motor gear?

gutter rock · 04-01-2017, 01:52 AM

That is reassuring. Shame that the basic ZX series had this problem, I really loved my ZX-5n but glad I sold it before it blew up. Happy to have a PZ-1P which seems immune to this problem. It really is a helluva camera. Funny how so many hesitate to call it a "pro" model, using terms such as "semi-pro" and such when modern "Pro" DSLR's have no chance of lasting decades like the PZ-1P.

**felixkh** · 09-26-2018, 12:32 AM - **2 Likes**

I know this thread is old, but I would like to share info on how to get the mirror motor gear repaired.

My MZ-S gear died in 2012 and no one in Singapore or Malaysia could fix it and so it stayed in my Dri cabinet until this year when a buddy when to Japan for a business trip and happened to find this company that can repair all older Pentax bodies and lenses. The company is staffed by former Pentax Engineers that were laid off by HOYA when they bought Pentax.

In my case the plastic gear had melted in the camera and so could not move the mirror.

The company is called NSB Tekunos.

Address is
265-1 .kakuyama.ogawa-machi.hiki-gun.saitama
355-0316
Attn: Mr Toshiyuki Nishimura
Tel: +81-493-59-8616 (Voicemail is in Japanese though, I cannot understand a word)

**OldChE** · 10-17-2018, 08:10 PM - **1 Like**

Originally posted by felixkh

I know this thread is old, but I would like to share info on how to get the mirror motor gear repaired.

My MZ-S gear died in 2012 and no one in Singapore or Malaysia could fix it and so it stayed in my Dri cabinet until this year when a buddy when to Japan for a business trip and happened to find this company that can repair all older Pentax bodies and lenses. The company is staffed by former Pentax Engineers that were laid off by HOYA when they bought Pentax.

In my case the plastic gear had melted in the camera and so could not move the mirror.

The company is called NSB Tekunos.

Address is
265-1 .kakuyama.ogawa-machi.hiki-gun.saitama
355-0316
Attn: Mr Toshiyuki Nishimura
Tel: +81-493-59-8616 (Voicemail is in Japanese though, I cannot understand a word)

Thanks for sharing your experience, this is good to know. I very much enjoy my MZ-S, which is still working and I hope it continues to do so - same with my ZX-L. However, my ZX-5N failed, so I know what this gear motor failure is like.

**felixkh** · 10-17-2018, 10:05 PM - **1 Like**

Originally posted by OldChE

Thanks for sharing your experience, this is good to know. I very much enjoy my MZ-S, which is still working and I hope it continues to do so - same with my ZX-L. However, my ZX-5N failed, so I know what this gear motor failure is like.

I think the weather also plays a part. I stay in a relatively high humidity region with all year summer so we do need to keep gear in dricabinets and if not things will break down and spoil.

Eyewanders · 10-18-2018, 08:59 AM - **3 Likes**

I still find it odd that so many MZ and Z variants have met their demise due to the failing of that drive gear, yet @felixkh 's account above is literally the only one I've read on these forums or otherwise specifically related to the MZ-S. Seems reasonable to assume that either the gear was switched in production at some early point, or that there is simply more to it relating to mechanical differences and other tolerances. I hope to never find out, but I've two replacement brass pieces on stand-by that I ordered 2 or 3 years ago. My MZ-S is still purring along happily and it was a very (already) well-used copy when I purchased it 4 (or 5?) years back. But then again, my MZ-3 is also just fine on with it's original gear. Knock on wood in both cases I suppose, however it's still interesting that we've simply heard of virtually no MZ-S failures in this regard beyond speculation and (that I know of) one direct account.

filmamigo · 10-23-2018, 06:56 AM - **1 Like**

I've had two MZ-S and I've sold both because of fear of eventual demise of a very expensive (to me) camera.

The "melting" issue in the MZ-S rang a bell, but not for the mirror gear. The only issue I experienced was with the weather sealing rings on the big control dials. My first MZ-S became almost impossible to adjust -- a trip to the local repair shop showed that the rubber rings had melted and were jamming the works. The shop cleaned out the rubber and it worked perfectly. So long as I was OK with not having weather sealing on those dials, it was great. My second MZ-S was a bit grabby on the dials but not as bad as the first, so I didn't have it cleaned out.

Of course in the mean time I've added an MZ-5n and MZ-3 to the collection. So far the MZ-3 is still going but the MZ-5n packed it in this summer. I ordered 2 custom replacement gears in brass in case I ever decide to have one of these cameras fixed. So maybe it's time to embrace the MZ-S, knowing that I have a gear in stock if it should ever fail?

**felixkh** · 10-30-2018, 04:10 PM

Originally posted by filmamigo

I've had two MZ-S and I've sold both because of fear of eventual demise of a very expensive (to me) camera.

The "melting" issue in the MZ-S rang a bell, but not for the mirror gear. The only issue I experienced was with the weather sealing rings on the big control dials. My first MZ-S became almost impossible to adjust -- a trip to the local repair shop showed that the rubber rings had melted and were jamming the works. The shop cleaned out the rubber and it worked perfectly. So long as I was OK with not having weather sealing on those dials, it was great. My second MZ-S was a bit grabby on the dials but not as bad as the first, so I didn't have it cleaned out.

Of course in the mean time I've added an MZ-5n and MZ-3 to the collection. So far the MZ-3 is still going but the MZ-5n packed it in this summer. I ordered 2 custom replacement gears in brass in case I ever decide to have one of these cameras fixed. So maybe it's time to embrace the MZ-S, knowing that I have a gear in stock if it should ever fail?

Yes, you should be using the MZ-S more often.

gutter rock · 10-30-2018, 06:42 PM

FWIW, There was an eBay auction for an MZ-S a few months ago with a broken mirror gear. Just some more evidence that at least some of these cameras have the plastic gear problem.

brofkand · 10-30-2018, 07:15 PM

I hope my MZ-S never suffers this issue. It's the best camera I've ever used for me.

Erik Leifson · 09-11-2019, 08:34 PM

Originally posted by filmamigo

I've had two MZ-S and I've sold both because of fear of eventual demise of a very expensive (to me) camera.

The "melting" issue in the MZ-S rang a bell, but not for the mirror gear. The only issue I experienced was with the weather sealing rings on the big control dials. My first MZ-S became almost impossible to adjust -- a trip to the local repair shop showed that the rubber rings had melted and were jamming the works. The shop cleaned out the rubber and it worked perfectly. So long as I was OK with not having weather sealing on those dials, it was great. My second MZ-S was a bit grabby on the dials but not as bad as the first, so I didn't have it cleaned out.

Of course in the mean time I've added an MZ-5n and MZ-3 to the collection. So far the MZ-3 is still going but the MZ-5n packed it in this summer. I ordered 2 custom replacement gears in brass in case I ever decide to have one of these cameras fixed. So maybe it's time to embrace the MZ-S, knowing that I have a gear in stock if it should ever fail?

That shutter ring was sticky on mine, as well. Almost welded to the body. What I did was spray some of that non-silicone dry lube (like you use for table saw tables) under the perimeter. It soaks in and leaves the film in there (didn't get under the lens, either). Work it back and forth while it evaporates, and it will move freely. Mine still turns just fine.

Erik Leifson · 09-11-2019, 08:47 PM

I love the MZ-S. It's my go-to because I like to spot meter everything. Canons and Nikon's make everything a hassle to easily manually shoot. Anyway, I pulled the bottom plate off of mine to take a gander at the infamous gear, but I found that the motor resides in a different location than in my MZ-3 (which I also pulled the plate off of). I couldn't see the gear from the bottom. However, if you shine a flashlight down the gap behind the lens on the left and actuate the depth of field preview, you can see the gears. If you can see down at a shallow angle, there is hiding down there what I believe to be THE gear in question. It's hard to tell, but it looks black to me, meaning plastic. Maybe someone else can look, too and confirm.

Erik Leifson · 09-11-2019, 08:50 PM

Picture didn't work. Here it is.

---------- Post added 09-11-19 at 08:56 PM ----------

Sorry, I'm new here. On a second look, it is possible that it is a brass, then plastic, then brass gear. If so, then the plastic gear in the middle was used to reduce noise (I assume). Someone else should verify. Sorry for the triple post.

**felixkh** · 09-13-2019, 02:54 AM - **3 Likes**

The way to identify if yours is a plastic gear is by serial number and the company name.

If your camera says Asahi Optical Company and serial number starts with 4xxxxxx, then it is the plastic gear.

If your camera says Pentax Corporation, and serial number starts with 5xxxxx, then it is brass gear.

https://i.ebayimg.com/images/g/i00AAOSw6pxdbiz6/s-l1600.jpg

I bought another Mint MZ-S on eBay near the end of 2017 and this also has the plastic gear, but so far so good.

Erik Leifson · 09-13-2019, 08:23 PM

Thanks for the clarification! On closer inspection, mine looked plastic (hard to see the hues in dim light). This just confirms this.

**Moe49** · 09-18-2019, 12:00 PM

Originally posted by felixkh

The way to identify if yours is a plastic gear is by serial number and the company name.
If your camera says Asahi Optical Company and serial number starts with 4xxxxxx, then it is the plastic gear.
If your camera says Pentax Corporation, and serial number starts with 5xxxxx, then it is brass gear.

My Silver MZ-S says "Asahi Optical Company, Ltd." and the s/n starts with 3xxxxxx, #3307293.
I guess I should assume it has the plastic gear.

If the plastic gear ever fails, I will be highly inclined to repair it with the metal gear, because the MZ-S is a very fine picture taker.

Here are some recent snapshots out of my MZ-S :
https://www.pentaxforums.com/forums/8-pentax-film-slr-discussion/53503-cool-...ml#post4520803
https://www.pentaxforums.com/forums/18-monthly-photo-contests/354228-denali-...ml#post4112501
https://www.pentaxforums.com/forums/26-mini-challenges-games-photo-stories/8...ml#post3765734

09-11-2019, 08:50 PM	#27
Erik Leifson New Member Join Date: Sep 2019 Posts: 4	Picture didn't work. Here it is. ---------- Post added 09-11-19 at 08:56 PM ---------- Sorry, I'm new here. On a second look, it is possible that it is a brass, then plastic, then brass gear. If so, then the plastic gear in the middle was used to reduce noise (I assume). Someone else should verify. Sorry for the triple post. Attached Images

09-18-2019, 12:00 PM	#30
Moe49 Loyal Site Supporter Join Date: Jan 2010 Location: Santa Cruz Mtns. Photos: Gallery \| Albums Posts: 874	Originally posted by felixkh The way to identify if yours is a plastic gear is by serial number and the company name. If your camera says Asahi Optical Company and serial number starts with 4xxxxxx, then it is the plastic gear. If your camera says Pentax Corporation, and serial number starts with 5xxxxx, then it is brass gear. My Silver MZ-S says "Asahi Optical Company, Ltd." and the s/n starts with 3xxxxxx, #3307293. I guess I should assume it has the plastic gear. If the plastic gear ever fails, I will be highly inclined to repair it with the metal gear, because the MZ-S is a very fine picture taker. Here are some recent snapshots out of my MZ-S : https://www.pentaxforums.com/forums/8-pentax-film-slr-discussion/53503-cool-...ml#post4520803 https://www.pentaxforums.com/forums/18-monthly-photo-contests/354228-denali-...ml#post4112501 https://www.pentaxforums.com/forums/26-mini-challenges-games-photo-stories/8...ml#post3765734 Last edited by Moe49; 09-18-2019 at 01:06 PM.

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04-01-2017, 01:52 AM	#16
gutter rock Junior Member Join Date: Oct 2016 Posts: 42 Original Poster	That is reassuring. Shame that the basic ZX series had this problem, I really loved my ZX-5n but glad I sold it before it blew up. Happy to have a PZ-1P which seems immune to this problem. It really is a helluva camera. Funny how so many hesitate to call it a "pro" model, using terms such as "semi-pro" and such when modern "Pro" DSLR's have no chance of lasting decades like the PZ-1P.

09-26-2018, 12:32 AM - 2 Likes	#17
felixkh Site Supporter Join Date: Nov 2008 Location: Singapore Photos: Gallery Posts: 1,201	I know this thread is old, but I would like to share info on how to get the mirror motor gear repaired. My MZ-S gear died in 2012 and no one in Singapore or Malaysia could fix it and so it stayed in my Dri cabinet until this year when a buddy when to Japan for a business trip and happened to find this company that can repair all older Pentax bodies and lenses. The company is staffed by former Pentax Engineers that were laid off by HOYA when they bought Pentax. In my case the plastic gear had melted in the camera and so could not move the mirror. The company is called NSB Tekunos. Address is 265-1 .kakuyama.ogawa-machi.hiki-gun.saitama 355-0316 Attn: Mr Toshiyuki Nishimura Tel: +81-493-59-8616 (Voicemail is in Japanese though, I cannot understand a word)

10-17-2018, 08:10 PM - 1 Like	#18
OldChE Loyal Site Supporter Join Date: May 2008 Location: Chicago area Photos: Gallery \| Albums Posts: 484	Originally posted by felixkh I know this thread is old, but I would like to share info on how to get the mirror motor gear repaired. My MZ-S gear died in 2012 and no one in Singapore or Malaysia could fix it and so it stayed in my Dri cabinet until this year when a buddy when to Japan for a business trip and happened to find this company that can repair all older Pentax bodies and lenses. The company is staffed by former Pentax Engineers that were laid off by HOYA when they bought Pentax. In my case the plastic gear had melted in the camera and so could not move the mirror. The company is called NSB Tekunos. Address is 265-1 .kakuyama.ogawa-machi.hiki-gun.saitama 355-0316 Attn: Mr Toshiyuki Nishimura Tel: +81-493-59-8616 (Voicemail is in Japanese though, I cannot understand a word) Thanks for sharing your experience, this is good to know. I very much enjoy my MZ-S, which is still working and I hope it continues to do so - same with my ZX-L. However, my ZX-5N failed, so I know what this gear motor failure is like.

10-17-2018, 10:05 PM - 1 Like	#19
felixkh Site Supporter Join Date: Nov 2008 Location: Singapore Photos: Gallery Posts: 1,201	Originally posted by OldChE Thanks for sharing your experience, this is good to know. I very much enjoy my MZ-S, which is still working and I hope it continues to do so - same with my ZX-L. However, my ZX-5N failed, so I know what this gear motor failure is like. I think the weather also plays a part. I stay in a relatively high humidity region with all year summer so we do need to keep gear in dricabinets and if not things will break down and spoil.

10-18-2018, 08:59 AM - 3 Likes	#20
Eyewanders Veteran Member Join Date: Jan 2008 Location: Land of the Salish Sea Photos: Gallery \| Albums Posts: 3,343	I still find it odd that so many MZ and Z variants have met their demise due to the failing of that drive gear, yet @felixkh 's account above is literally the only one I've read on these forums or otherwise specifically related to the MZ-S. Seems reasonable to assume that either the gear was switched in production at some early point, or that there is simply more to it relating to mechanical differences and other tolerances. I hope to never find out, but I've two replacement brass pieces on stand-by that I ordered 2 or 3 years ago. My MZ-S is still purring along happily and it was a very (already) well-used copy when I purchased it 4 (or 5?) years back. But then again, my MZ-3 is also just fine on with it's original gear. Knock on wood in both cases I suppose, however it's still interesting that we've simply heard of virtually no MZ-S failures in this regard beyond speculation and (that I know of) one direct account.

10-23-2018, 06:56 AM - 1 Like	#21
filmamigo Pentaxian Join Date: Aug 2007 Location: Toronto Photos: Gallery \| Albums Posts: 797	I've had two MZ-S and I've sold both because of fear of eventual demise of a very expensive (to me) camera. The "melting" issue in the MZ-S rang a bell, but not for the mirror gear. The only issue I experienced was with the weather sealing rings on the big control dials. My first MZ-S became almost impossible to adjust -- a trip to the local repair shop showed that the rubber rings had melted and were jamming the works. The shop cleaned out the rubber and it worked perfectly. So long as I was OK with not having weather sealing on those dials, it was great. My second MZ-S was a bit grabby on the dials but not as bad as the first, so I didn't have it cleaned out. Of course in the mean time I've added an MZ-5n and MZ-3 to the collection. So far the MZ-3 is still going but the MZ-5n packed it in this summer. I ordered 2 custom replacement gears in brass in case I ever decide to have one of these cameras fixed. So maybe it's time to embrace the MZ-S, knowing that I have a gear in stock if it should ever fail?

10-30-2018, 04:10 PM	#22
felixkh Site Supporter Join Date: Nov 2008 Location: Singapore Photos: Gallery Posts: 1,201	Originally posted by filmamigo I've had two MZ-S and I've sold both because of fear of eventual demise of a very expensive (to me) camera. The "melting" issue in the MZ-S rang a bell, but not for the mirror gear. The only issue I experienced was with the weather sealing rings on the big control dials. My first MZ-S became almost impossible to adjust -- a trip to the local repair shop showed that the rubber rings had melted and were jamming the works. The shop cleaned out the rubber and it worked perfectly. So long as I was OK with not having weather sealing on those dials, it was great. My second MZ-S was a bit grabby on the dials but not as bad as the first, so I didn't have it cleaned out. Of course in the mean time I've added an MZ-5n and MZ-3 to the collection. So far the MZ-3 is still going but the MZ-5n packed it in this summer. I ordered 2 custom replacement gears in brass in case I ever decide to have one of these cameras fixed. So maybe it's time to embrace the MZ-S, knowing that I have a gear in stock if it should ever fail? Yes, you should be using the MZ-S more often.

10-30-2018, 06:42 PM	#23
gutter rock Junior Member Join Date: Oct 2016 Posts: 42 Original Poster	FWIW, There was an eBay auction for an MZ-S a few months ago with a broken mirror gear. Just some more evidence that at least some of these cameras have the plastic gear problem.

10-30-2018, 07:15 PM	#24
brofkand Pentaxian Join Date: May 2009 Location: North Carolina Posts: 836	I hope my MZ-S never suffers this issue. It's the best camera I've ever used for me.

09-11-2019, 08:34 PM	#25
Erik Leifson New Member Join Date: Sep 2019 Posts: 4	Originally posted by filmamigo I've had two MZ-S and I've sold both because of fear of eventual demise of a very expensive (to me) camera. The "melting" issue in the MZ-S rang a bell, but not for the mirror gear. The only issue I experienced was with the weather sealing rings on the big control dials. My first MZ-S became almost impossible to adjust -- a trip to the local repair shop showed that the rubber rings had melted and were jamming the works. The shop cleaned out the rubber and it worked perfectly. So long as I was OK with not having weather sealing on those dials, it was great. My second MZ-S was a bit grabby on the dials but not as bad as the first, so I didn't have it cleaned out. Of course in the mean time I've added an MZ-5n and MZ-3 to the collection. So far the MZ-3 is still going but the MZ-5n packed it in this summer. I ordered 2 custom replacement gears in brass in case I ever decide to have one of these cameras fixed. So maybe it's time to embrace the MZ-S, knowing that I have a gear in stock if it should ever fail? That shutter ring was sticky on mine, as well. Almost welded to the body. What I did was spray some of that non-silicone dry lube (like you use for table saw tables) under the perimeter. It soaks in and leaves the film in there (didn't get under the lens, either). Work it back and forth while it evaporates, and it will move freely. Mine still turns just fine.

09-11-2019, 08:47 PM	#26
Erik Leifson New Member Join Date: Sep 2019 Posts: 4	I love the MZ-S. It's my go-to because I like to spot meter everything. Canons and Nikon's make everything a hassle to easily manually shoot. Anyway, I pulled the bottom plate off of mine to take a gander at the infamous gear, but I found that the motor resides in a different location than in my MZ-3 (which I also pulled the plate off of). I couldn't see the gear from the bottom. However, if you shine a flashlight down the gap behind the lens on the left and actuate the depth of field preview, you can see the gears. If you can see down at a shallow angle, there is hiding down there what I believe to be THE gear in question. It's hard to tell, but it looks black to me, meaning plastic. Maybe someone else can look, too and confirm.

09-13-2019, 02:54 AM - 3 Likes	#28
felixkh Site Supporter Join Date: Nov 2008 Location: Singapore Photos: Gallery Posts: 1,201	The way to identify if yours is a plastic gear is by serial number and the company name. If your camera says Asahi Optical Company and serial number starts with 4xxxxxx, then it is the plastic gear. If your camera says Pentax Corporation, and serial number starts with 5xxxxx, then it is brass gear. https://i.ebayimg.com/images/g/i00AAOSw6pxdbiz6/s-l1600.jpg I bought another Mint MZ-S on eBay near the end of 2017 and this also has the plastic gear, but so far so good.

09-13-2019, 08:23 PM	#29
Erik Leifson New Member Join Date: Sep 2019 Posts: 4	Thanks for the clarification! On closer inspection, mine looked plastic (hard to see the hues in dim light). This just confirms this.