Minolta Hi-Matic F issue

[jojonas]

Hello from Sweden!

I got my hands on a Minolta Hi-Matic F that seemed to be in nice condition but I can't get it to work as is and I haven't found someone with the same specific problems.
I thought I'd check if anyone recognized the faults and could steer me in the right direction to what needs fixing.

Works:
Shutter button - goes down and sounds like it triggers something.
Advance lever - travels well, activates the film winding and unlocks the shutter button
Battery tester - two LR44 batteries seems to work when pressing the button and it lights up well

Doesn't work:
Shutter - doesn't move at all. Either with or without batteries
Low light warning - doesn't active at half press. I read in the manual that the batt. test lamp should light up as well on low light, but it does not.

Besides that the focusing, rangefinder and setting adjustments seems to work fine. The frame counter has only gone up since I got the camera. Though I have not tried with film yet.

My own thoughts so far..
I thought it was just the shutter that might be stuck with gunk but the low light warning makes me worry about an electrical fault.
Anyone recognize these symptoms on this model?

 

[xkaes]

It's not just that model. All of the other Hi-Matics with the "ATOM" symbol (E, ES, F, FP, CS) use a special COPAL shutter that combines the aperture blades and the shutter blades together. COPAL did the same for many of the Yashica G35 rangefinder, as well. Minolta called it "ELECTRO-CONROL", but they were auto-exposure only, since the shutter and aperture blades were the same. They also have the "ATOM" symbol.

These shutters are great when they work, but apparently the electronics are "complicated" and reliability is not their strength. Are you sure you are using the correct battery. I thought they all used 640 batteries.

 

[OAPOli]

This model is notorious for suffering from battery corrosion, which eats the negative power wire.

I had one which had similar symptoms as yours, although I think that the battery test didn't work. So I suppose the wire is ok, but there is a loss of power to the electromagnet of the shutter.

You would need to disassemble the camera down to the shutter board and test for continuity. It's not the easiest camera to work on; small and cramped.

Minolta HI-MATIC Fの修理 - mglss studio photography

 

[jojonas]

These shutters are great when they work, but apparently the electronics are "complicated" and reliability is not their strength. Are you sure you are using the correct battery. I thought they all used 640 batteries.

I am not using the original 640 batteries, no. But this camera is rather well documented on working fine with two lr44s instead imho.

...but I found one instance of one person claiming that 1.5 V did not work for his but 1.4 V did so I'm thinking I should try that before heating up the soldering iron.


edit: Thanks OAPOli. Did the 640s emit some gasses? that might be why hearing aid batteries have holes in them ig. well, I'll put it on my #2 to test

 

[4season]

I've owned 4 of those cameras, and every one of them needed servicing, but IMO it's generally worthwhile as they are fun to use, and the diamond-shaped aperture produces highlights which "sparkle" due to diffraction.

2x 1.5 volt LR44 batteries work well. I 3D-printed simple adapters.

If I were experiencing problems with the battery-test switch, I'd examine the switch for corrosion. Unfortunately, the original batteries contained a lot of electrolyte, and I've seen instances were the electrolyte wicked through the wiring, reached the switch, and badly corroded it. Hopefully, yours isn't too bad.

 

[jojonas]

oh, I love a camera that has a nice characteristic. thank you for the photo example, 4season!

but electrolyte huh? interesting

 

[OAPOli]

In my case the black (negative) wire was completely corroded, and also affected the terminal on the top of the camera. After replacing the wire, the camera worked correctly.