Mamiya 7 + 80mm combo - won't fire in mild cold

[ediz7531]

Hi there,

I have a Mamiya 7 + 80mm combo. The camera has operated fine until recently, when on a couple of rolls in mild cold weather (~ 40 -45 F) outside, the camera wouldn't fire. The light meter and the battery check were working just fine during the outing, however. When I got home and let the camera come to room temperature, I was able to fire the shutter just fine. Note that I used a brand new battery on the second roll when this happened, so it wasn't caused by a particular battery. To isolate the issue, I then did the following at home:

- I put the camera and lens in the fridge (36F) for 30 minutes or so, with film loaded. Took it out. It wouldn't fire.
- I then put the lens in the fridge for 30 minutes, but left the camera out, film loaded still. It fired just fine.
- I then put the camera and battery in the fridge for 30 minutes, film loaded. The lens stayed outside. It wouldn't fire.
- Finally, with the camera in the cold, swapping the battery to a warm one, I'm able to fire the shutter just fine (film still loaded).
- Also with the camera in the cold, and with film *not* loaded, I'm able to fire the shutter just fine.
* Note: in all of the above, the light meter and the battery check functions worked just fine.

I understand that electronics may be erratic at low temperatures, but these are above-freezing temperatures. Is this normal? If not, is it repairable? The camera was CLA'd last year by PCW.

 

[Dan Daniel]

I am not familiar with the electronics in this camera, but it sounds like a bad wiring connection. In warmer temperatures, there is enough reserve in the battery to deliver working power. But as it cools, its reserve drops and it doesn't have what it takes to overcome the resistance of a bad connection somewhere? Or some part of the circuit itself has reduced function as it cools.

There's the old pencil eraser rubbing on the battery connections thing to remove oxidation or such at this point in the circuit. No idea what else can be traced. A schematic might show expected voltages at various points in the circuit.

 

[Steve Goldstein]

Years ago I had an intermittent connection in my Mamiya 7, I don’t remember if it was cold-related. I took off the lens and gently cleaned the contacts on the lens mount and camera body with a pencil eraser followed by a cotton cloth. That cured it.

 

[MattKing]

Don't discount the possibility that the new battery isn't doing the job.
Are you using alkaline, silver oxide or lithium versions of the battery?

 

[Sirius Glass]

It sounds like the camera and lens need a CLA which should clean out the old lubricates, relubricate with fresh lubricates, check the electronics and adjust the shutter.

 

[gone]

If the battery voltage has been tested and the electrical contacts are clean, could be the shutter button. I've had a number of electronic cameras that had issues in cold weather. What often got them fixed was to take a tiny drop of electrical cleaner/diluted w/ lighter fluid, and place it the edge of the shutter button. Then press the button quickly about 10 times to clean it up in there.

 

[mshchem]

I would get on Ebay and find a US seller of fresh Japan made cells. I went through something similar with a Mamiya 6mf. Got some nice fresh silver oxide cells works fine. Some cameras allow you to hook a cable to the camera and keep the batteries in a holder under your coat. Battery performance drops dramatically with cold.

 

[Tom Kershaw]

I would get on Ebay and find a US seller of fresh Japan made cells. I went through something similar with a Mamiya 6mf. Got some nice fresh silver oxide cells works fine. Some cameras allow you to hook a cable to the camera and keep the batteries in a holder under your coat. Battery performance drops dramatically with cold.

I have been using these with my Mamiya 7ii: https://www.smallbattery.company.org.uk/sbc_2cr1-3n_sanyo.htm

 

[ediz7531]

Thanks all for the responses.

To questions about the batteries: One was an alkalike (28A), the other a lithium (28L) battery. Made by Duracell.

 

[MattKing]

Which battery was the old one?
The alkaline batteries have a lot less capacity, their voltage will change over time, and they are much more likely to be partially depleted right out of the package.
They are relatively cheap, so I keep them (for my 645 Pro) as emergency backups.

 

[mshchem]

Thanks all for the responses.

To questions about the batteries: One was an alkalike (28A), the other a lithium (28L) battery. Made by Duracell.

Yeah, not good idea in general to mix lithium and alkaline. There's a subtle difference in voltage. Get some nice fresh cells.

 

[mshchem]

I have been using these with my Mamiya 7ii: https://www.smallbattery.company.org.uk/sbc_2cr1-3n_sanyo.htm

Very nice!

 

[ediz7531]

Which battery was the old one?
The alkaline batteries have a lot less capacity, their voltage will change over time, and they are much more likely to be partially depleted right out of the package.
They are relatively cheap, so I keep them (for my 645 Pro) as emergency backups.

Lithium is the "old" one (a few months old). Alkaline, new.

Yeah, not good idea in general to mix lithium and alkaline. There's a subtle difference in voltage. Get some nice fresh cells.

I don't quite follow. There is no mixing happening. The camera takes only one 6v battery at a time.

 

[mshchem]

Lithium is the "old" one (a few months old). Alkaline, new.


I don't quite follow. There is no mixing happening. The camera takes only one 6v battery at a time.

Aha, I am mistaken. This takes a proper battery like my RZ67 II. I was thinking it was similar to my 6MF that uses 2 button cells. Never mind me.

What battery type does Mamiya recommend? For some reason I have in my mind that silver oxide has better low temperature performance???

 

[mshchem]

THIS IS WHAT YOU NEED A BATTERY CASE YOU PUT IN YOUR FRONT POCKET TO KEEP THE BATTERY WARM THIS IS FOR A MAMIYA 7, PROBABLY SOMEONE HAS ONE ON EBAY

 

[MattKing]

The old one was probably mostly used up, and the new one was probably partially discharged due to age.
The silver oxide and lithium version are preferable.

 

[mshchem]

Alkaline batteries die a long slow death. This is probably what got you in trouble. I had a fancy Sony digital display, SW radio that would automatically shut down at a threshold voltage. Drove me nuts. A old mechanical tuner radio was much more reliable. As the batteries aged the volume got weaker and weaker but the radio still worked.

 

[nicelynice]

I made a comment on your Reddit post, but let me repost here unless anyone else is looking for similar info:
---
I'm not sure about the Mamiya 7, but I was inquiring with a camera tech about the Mamiya 6 for winter mountaineering. He said that the lenses are generally fine until about -10C, but that the film release mechanism (that allows you to shoot after advancing the film) can become unreliable when the lubricants inside start getting colder. Given your tests, it seems like the film release may the culprit, rather than the electronics. It seems this part may need looking at by a tech. I wasn't sure if the lubricants themselves were the problem, or if the stiff lubricants exacerbate an already problematic part.

 

[ediz7531]

I made a comment on your Reddit post, but let me repost here unless anyone else is looking for similar info:
---
I'm not sure about the Mamiya 7, but I was inquiring with a camera tech about the Mamiya 6 for winter mountaineering. He said that the lenses are generally fine until about -10C, but that the film release mechanism (that allows you to shoot after advancing the film) can become unreliable when the lubricants inside start getting colder. Given your tests, it seems like the film release may the culprit, rather than the electronics. It seems this part may need looking at by a tech. I wasn't sure if the lubricants themselves were the problem, or if the stiff lubricants exacerbate an already problematic part.

Thank you. I ended up sending the camera to PCW again for an inspection and repair. Bob Watkins speculated over email that it could be that the source of this issue is a magnet. A little googling around indicates that this is associated with the film mechanism. I’m hoping it’s a fixable problem.

 

[Cinema]

i remember visiting bob in his workshop near skokie when i was a kid. he is the best in the business and will likely find the culprit