Transiently autonomous self-timer problem

Truzi · Sep 22, 2014

Perhaps someone can give me some advice on my Sears KS-2 (Ricoh XR7). It is a very rare and transient problem, happening about 3 times in the past 10 years.
It was my Grandfather's camera, so it has sentimental value; I am keeping it and using it.

The self-timer and shutter are electronic.
The problem is, after taking a picture (by pressing the shutter button) and winding, the self-timer starts beeping. If I then press the self-timer button it will stop (cancel), but will start again on it's own. If I let it go it will fire the shutter, and will repeat it's behavior after I wind. Fiddling with the ASA ring and compensation dial had no effect. Removing the battery does not prevent the problem from continuing, and spontaneous remission has happened even with a good battery installed. Duration is about 3 days.

I _rarely_ use the self-timer in general, and never have when this has happened. The button is not accidentally touched, and is in the correct "up" position (it is spring-loaded). When it is NOT happening, I can play with the self-timer button all I want with no issues.

I had suspected the problem may be related to humidity, but cannot confirm this.
Canned air was used to try to blow around the button and crevices to no effect. However, when inverting the can and accidentally getting the propellant on the area, it did stop... until it warmed again (I could replicate this). So I'm pretty sure it is localized to the micro-switch or the immediate area.

The button presses on a micro-switch, so the solution is probably to replace the switch, but I am reluctant to do so at this point (and the camera is fine right now). I also do not trust my soldering skills on what is likely a ribbon (I could handle a PCB). I do have a repair manual and box of donor cameras, but it seems a shame to rip open the camera for something that may not happen again for a few years.

Are there any suggestions that do not require disassembly?

shutterfinger · Sep 23, 2014

A google search for Richo XR7 service manual resulted in Dead Link Removed which requires you to register to download and also pops up ads. Further down the list is https://servicecamera.wordpress.com/tag/ricoh-xr-7/ . It appears to be a cleaner copy of the manual and for $10 less hassle.

It could be dirt causing the main chip to respond as if the self timer button was pressed but if cleaning it does not solve the problem its the main chip going/gone bad.

rbultman · Sep 23, 2014

Not sure if this camera pre-dates RoHS lead removal, but I would guess tin whiskers. Or maybe connector corrosion, although with that o would expect the opposite behavior. If you feel comfortable taking of the covers, check all connections.

Sent from my Nexus 5 using Tapatalk

Xmas · Sep 23, 2014

selfie for avtar...

yea flexi rigid one piece (probably) dont try.

AgX · Sep 23, 2014

How could evaporation cooling (as it seemed to have happened) have effect on that circuit running without substantial load?

Xmas · Sep 23, 2014

eg evaporation causing cooling and relative contraction between copper and plastic of flexi rigid...

The flexi rigid is an invention of the devil.

Some circuits switch on break of make and break.

They are nice cameras otherwise

E. von Hoegh · Sep 23, 2014

Truzi said:
Perhaps someone can give me some advice on my Sears KS-2 (Ricoh XR7). It is a very rare and transient problem, happening about 3 times in the past 10 years.
It was my Grandfather's camera, so it has sentimental value; I am keeping it and using it.

The self-timer and shutter are electronic.
The problem is, after taking a picture (by pressing the shutter button) and winding, the self-timer starts beeping. If I then press the self-timer button it will stop (cancel), but will start again on it's own. If I let it go it will fire the shutter, and will repeat it's behavior after I wind. Fiddling with the ASA ring and compensation dial had no effect. Removing the battery does not prevent the problem from continuing, and spontaneous remission has happened even with a good battery installed. Duration is about 3 days.

I _rarely_ use the self-timer in general, and never have when this has happened. The button is not accidentally touched, and is in the correct "up" position (it is spring-loaded). When it is NOT happening, I can play with the self-timer button all I want with no issues.

I had suspected the problem may be related to humidity, but cannot confirm this.
Canned air was used to try to blow around the button and crevices to no effect. However, when inverting the can and accidentally getting the propellant on the area, it did stop... until it warmed again (I could replicate this). So I'm pretty sure it is localized to the micro-switch or the immediate area.

The button presses on a micro-switch, so the solution is probably to replace the switch, but I am reluctant to do so at this point (and the camera is fine right now). I also do not trust my soldering skills on what is likely a ribbon (I could handle a PCB). I do have a repair manual and box of donor cameras, but it seems a shame to rip open the camera for something that may not happen again for a few years.

Are there any suggestions that do not require disassembly?

See if the timer button is pressing the microswitch to the point where it almost trips. Check any connectors and soldered connections in the immediate vicinity of where you got the canned air.

I don't know this camera, but those are the things I'd check based on your symptoms.

fstop · Sep 23, 2014

AgX said:
How could evaporation cooling (as it seemed to have happened) have effect on that circuit running without substantial load?

I'll let you in on a little secret~
We use freeze spray all the time for troubleshooting electronic components, a failed component will come back to life once sprayed.

The button may be springing back up but the contact(s) may still be engaged.I'll try to find a better manual.

E. von Hoegh · Sep 23, 2014

fstop said:
I'll let you in on a little secret~
We use freeze spray all the time for troubleshooting electronic components, a failed component will come back to life once sprayed.

The button may be springing back up but the contact(s) may still be engaged.I'll try to find a better manual.

Yes indeed, it's wonderful for finding thermal intermittents. And we no longer need to worry about hitting a tube with it.

John Koehrer · Sep 23, 2014

Since you have some donor cameras you could pull the cover off one & examine what's there, flex or board.
Soldering to a flex isn't really more difficult than a board with an appropriate iron.

AgX · Sep 23, 2014

fstop said:
We use freeze spray all the time for troubleshooting electronic components, a failed component will come back to life once sprayed.

I know, but I thought it was just effective on semiconductors overloaded by some external or internal fault.

And I did not think of mechanical issues (shrinking of contacts etc.) either.

Xmas · Sep 23, 2014

If it is low frequency ignore it.

If it becomes regular post again.

Truzi · Sep 23, 2014

Thanx, there is a lot of good advice so far.

I thought perhaps the microswitch was weak (spring tension), or something was interfering with it's travel (from the cooling thus contraction and easier movement), but had not considered any breaks in the solder or traces - which is odd because it is the sort of thing I should have known to consider.

Only the button and top-plate area were sprayed/cooled. I've not taken it apart. I'm sure some of the propellant got through the space around the button.

I do have an hard copy of the repair manual, but don't feel confident opening the camera up yet (though had the bottom plate off once). I have collected a box of compatible "broken" cameras in case I ever need parts. (So far, the "broken" cameras either had only dead batteries, or disintegrating seals gumming the shutter. Only one was truly broken (apparently dropped on it's lens, tweaking the mount and mirror box).)

Someday, when I have time, I will practice a full tear-down and reassembly of one of the donor cameras, before hurting my Grandfather's camera.

The problem happened for 5 minutes about two years ago, and for 3 days a month or so ago - on vacation. It was annoying to put the shutter dial on lock until I was ready to snap a picture.

It has been working fine recently. Wasted some film at lunch with no issues. I'm trying to decide whether it should be a small winter project, or if it's complicated enough to use the HAL 9000 method of diagnosis.

Xmas · Sep 23, 2014

Hi Trusi

Please rebuild a broken one & keep gpaps intact.
Nostalgia rules

Noel

E. von Hoegh · Sep 23, 2014

AgX said:
I know, but I thought it was just effective on semiconductors overloaded by some external or internal fault.

And I did not think of mechanical issues (shrinking of contacts etc.) either.

It works only on thermally activated faults. It will not 'fix' a broken component. Experience since 1975 or so...

benjiboy · Sep 24, 2014

If the camera was your grandfathers and is of such great sentimental value , I suggest you have it repaired by a professional.

Truzi · Sep 24, 2014

benjiboy said:
If the camera was your grandfathers and is of such great sentimental value , I suggest you have it repaired by a professional.

Been there, done that. I'm not fond of the idea of shipping the camera.

Around 2010, I did take it to a pro-shop chain in Cleveland, Ohio, USA, that advertises film camera repair. The shutter would jam periodically, it had a broken plastic bezel/rewind crank (you pull on the bezel to unlock the film door), and it had developed light leaks. They didn't fix any of it right after three attempts. I figured that I, too, could not fix it after three tries... I was wrong; got it right the first time.

That is why I now own a service manual and a box of compatible donor cameras (and have ceased patronage). It is also what led me to discover APUG.

The shutter problem was from bits of degraded foam light seal getting on it, causing it to stick until the debris dried. I cleaned the light-traps myself and resealed with yarn and felt. The shutter has been fine ever since.

They "fixed" the light leak by replacing the back with another old back - never touching the light seals on the body. This "new-old" back has the slot for the end of a box of film, which I'd always wanted, though I'm thinking of swapping the original style back for nostalgic reasons.

The bezel was just age, but they replaced it with the wrong bezel and shaft (bezel too thick, shaft too short), causing the shaft to lose contact with the cartridge spool when rewinding - leading me to believe I'd completely rewound the film (lack of resistance), only to expose it when opening the back. I fixed that with the correct parts from a donor camera. (Strangely, the problem only occurred with Kodak cartridges - probably only 1 or 2 mm difference.)

I hear we have a shop in Parma, Ohio, that is very good with older cameras. If they still do repairs, I may test them with my folding 35mm Contessa; it's rough, but has little sentimental value.

Xmas · Sep 24, 2014

HiTrusi

In your shoes Id ask family.
If it only fails ocassionally ignore.
Nephews or Niece may want it as it is to shoot or shelve. Some may be more afflicted by nostalgia than you.

Noel
x

John Koehrer · Sep 24, 2014

It may also be a cold solder joint on a board or flex.

But maybe it's a poltergeist or grandpa paying a visit?

MattKing · Sep 24, 2014

I cannot help you with the problem.

But the thread title would make an interesting music album title.

shutterfinger · Sep 24, 2014

Your camera is not a Ricoh XR7 rebadged Sears KS2. Sears contracts companies to make their products for them. Sears engineers look over the companies design and make changes they think will improve reliability. Most companies use a base model then offer variations of that base as other makes. The differences are usually minor such as a different switch.
This may explain the wrong bezel and shaft.

And yes, the body or switch mounting may have changed shape due to heat and age causing it to make contact intermittently. I have also encountered solid state devices such as transistors and IC chips that would malfunction, cool down and repair themselves then operate for another 100 hours or more before failing permanently.

Truzi · Sep 25, 2014

This is very similar to parts interchange in auto repair, which I am more familiar with.

I know how Sears used to make changes (in a much different manner than they do today). I've repaired mid-90s and earlier Sears power tools and lawn equipment with no problems using OEM parts for the OEM models. Up until the 90s, Sears didn't change mechanical parts too much, and relied on the manufacturer to engineer the changes they did want. Increased reliability wasn't the impetus - and it is even less so now (which is why I'm not giving up my father's early 90s Craftsman mower, and will not buy anything labeled "Craftsman" today).

The shafts and bezels are exactly the same on my donors. My guess is the camera shop used something from a different Sears/Ricoh series (or just something that looked "close enough" - and I could tell the bezel was different when I first saw it).

So far I have 18 donor cameras, a mix of KS-2, KS Super, XR-6, XR-7, and a few other models. I've not ripped apart any of these cameras yet, but the external differences are cosmetic. Doors, buttons, battery holder, etc. are the same, with some color or printing differences. I don't expect much, if any, internal differences.

I know some of the models have different/fewer functions. For example, the KS Super and its Ricoh equivalent don't have shutter speeds; just Auto, Flash sync (125), bulb, and lock - basically just flash & aperture priority. There are models without Exposure Lock or DOF preview, etc. (forget which ones, but I did do my research on interchange a few years ago and have a list somewhere).

To re-engineer the complex mechanisms would not make good business sense, though certainly different (cheaper) materials and components might have been used. Also, it would be bad business sense to make a different electronic shutter for each model/brand - so most differences are likely in the circuitry. I'm confident the vast majority of mechanical parts will interchange with no problems.

I suppose I'll know for sure when I start disemboweling them, lol.
If you have specifics, please share - it will definitely come in handy (though I'd never be able to do things like in your shutter repair thread).

shutterfinger · Sep 25, 2014

I worked for a hardware sore chain that was purchased by Sears. Every product we carried that was changed to Sears brand came from the same manufacturer as the product we had been carrying. The OEM item was different and most parts would not interchange. They went bankrupt and were bought by Lowes. Sears drills were made by Ryobi and had better on/off switches than Ryobi's drills. Sears was only concerned with failures while in warranty.

I have not gotten into servicing 35mm SLR's. If you get stumped on something post some pictures, I might be able to supply some useful input.

Truzi · Sep 25, 2014

I completely agree, in regard to items over the past decade or two.
The "Sears" power tools we have are ~ 25 years old or more, and still work well. This is when they were typically made by Black and Decker and the like, and savings were based more on volume purchasing than inferior materials/design. Modern manufacturing makes it very easy for the OEMs to make sweeping substitutions. Some of the power tools I inherited are older than me, and have given me no need to replace them. I miss the old Craftsman quality.

I'm not impressed with Ryobi in general. (I do have one of their drills (my mother creates large messes in the house; I couldn't find the "good" drill and was in the middle of something, so ran out and got the cheapest I could find)).

In the future I may have a question about an old 120 Sears folder. It's certainly on the back-burner at the moment, but would perhaps be an easier fix. It belonged to a deceased relative, and when someone gives me a family camera, I feel compelled to use it at least a few times. I don't know exactly what it is, except it was a cheap model, and the little spring-shutter doesn't work well enough to try some film. Unfortunately, the shutter casing is riveted (I've a problem reassembling things, and it is patience-related).

As for the KS-2, I think I'll follow the advice to let it go until it becomes a regular issue (or until I've successfully redone a practice camera). This thread has given me a few more ideas I'd not originally thought of, so I feel better prepared.
I wish there were an easy way to get it back to normal on the rare occasion it does happen - but it's not like it renders the camera unusable.

Transiently autonomous self-timer problem

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