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scott
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, July 23, 2005 - 08:06 pm: | 
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Hi Everyone. For those of you who think this looks familiar- it is. I posted regarding the same problem a while back but due to the reoccuring answer that I am not convinced is the solution I am posting again.
So from the start please do not tell me to take out the front element of my lens and put lighter fluid on the shutter blades. This does not seem to be a definite fix for anyone who has tried it and I'm not about to do that yet!
My hi matic 7s has a sporatically operating shutter. Sometimes it's fine and sometimes not.
When it works- As you wind the advance lever there is a definite ticking noise similar to that of the self timer being set or ticking to release. When it makes this sound I know the shutter will fire.
When it doesn't- The advance is hollow and there is no ticking sound. I know it will not fire then.
If anyone has any idea of the mechanism that makes this sound, where it is located and what it looks like please contact me.
Please don't tell me about lighter fluid. |
Dan Mitchell
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, July 24, 2005 - 12:13 am: |
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Take the two screws out of the bottom and remove the bottom cover. (Watch out for the little plastic thingy around the tripod mount. It may fall out.) The tick-tick-tick ratchet sound is caused by a pawl hitting the stepped cam located between the winder gears and shutter cocking lever. This cam allows for the partial stroke winder feature. There is a lever moved by a spring that drops into a big gap in that stepped cam and acts as a double-wind prevention mechanism. A lever attached to that cam is what tensions the shutter. OK?
Now - when the shutter fails to complete its cycle, the double-wind prevent is let off, but the main tensioning arm does not return to its starting position. That means you can move the winder, but it doesn't do anything.
There are several potential points of failure. The MOST LIKELY is the shutter did not release because something is gummed up. That's why people keep telling you to clean the shutter.
A second possibility is the ratchet pawl is gummed up or the spring is worn/broken.
Third is the idler gear can get stripped. Notice that it only rotates 180 degrees on each wind so it may work sometimes and not others.
In any case, I've worked on 6-7 of these Hi-matics and in all but one case the problem was a dirty shutter. Unfortunately, that particular shutter has a complex auto-exposure feature that can have many little problems. Just cleaning the blades may not be enough and you may have to remove and completely clean the shutter. That's a major task on a Hi-matic, unfortunately.
Bottom line - if you don't see anything in the winding gears that is stripped or broken you need to keep flushing the shutter until it is completely clean. |
Sjtornga
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, August 02, 2005 - 07:55 am: |
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I appreciate your feedback.
There is something I don't understand or that I am unable to communicate. I think the noise I am referring to is different than the one you are describing. It is very clocklike. I can see and hear the noises you describe when I remove the bottom cover.
The noise that is missing occurs about a third of the way through the wind stroke. It's like gears being forced and a ticking. Similar to on an SRT when you move to bulb setting. When that noise is not there the shutter will not fire.
If my shutter is gummed up why is it that it works sometimes and not others and only in conjunction with the sound that is absent or present? |
WernerJB
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, August 02, 2005 - 11:34 am: |
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In those Hi-Matics there is that "second sound" when you cock the shutter preset to longer exposure times, a sec. or half a sec., it is produced by the clockwork inside. On the other hand this has nothing to do with its basic function, and a shutter that is just partly gummed up may sometimes work. I wouldn't spend too much time finding out theoretically what's wrong with it, if I were you I would follow D. Mitchell's advice, there is no alternative than cleaning the shutter thoroughly or live with one that fails every now and then! |
scott
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, August 03, 2005 - 08:29 pm: |
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I'm concerned about unscrewing the lens and making the focus inaccuarte.
I don't have a working himatic available to me at the moment I write this but I'm almost certain it makes that second noise on all the shutter speed settings. Also if it has nothing to do with the basic function why is it there when the shutter fires and not when it doesn't?
I'm apprehensive because it's in such excellent cosmetic condition and it hasn't been messed with........ Yet! |
WernerJB
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, August 04, 2005 - 12:28 pm: |
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I'm afraid you have to decide to do it, have somebody else do it for you ar leave things as they are. You can definitely not solve the problem by getting lost in ifs, buts or ands. When I worked on my first Hi-M 7 I had no idea of what I was into and, of course, the whole project ended in what I thought was a disaster. Later I discovered that a lever in the aperture mechanism had been beyond repair before I had worked on the camera. Experiencing this gave me the courage to start a new repair attempt, and as I had gathered enough info/knowledge on this type of camera I managed to get that second one to full working order, including the fixing of the so-called "wobbly lens" for which this camera is notorious.
my advice is, learn or practise on a junker, if your camera means too much to you now and leave it for later when you feel more confident. |
Dan Mitchell
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, August 04, 2005 - 03:52 pm: |
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From what you've said the problem is almost certainly contamination in the shutter. The only way to fix it is clean the shutter. A dirty shutter can be erratic depending what type of stuff is in there.
Removing the front and rear lens groups will not alter the focus on this camera.
Like Werner said, you may want to buy a junker and practice on it first. They are cheap and readily available. |
