Fungus in GSN Lens

Harlee

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Sep 6, 2005
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I picked up a really dirty GSN today at a thrift shop for $15, not knowing if it was in working order. I offered the clerk $10 when I noticed that there was a battery left in it that had corroded, but the corrosion wasn't bad, primarily on the battery cap. I also noticed that there was some fungus in the lens, but since I had two GSN parts cameras in a box in the garage, I decided to take the challenge, since the clerk was adament, $15.

When I got home, I cleaned up the battery cap, placed a battery adapter and a battery in it, and behold, everything is working. Clunks when I rewind it, although I may replace the POD anyway, exposure lights both work, shutter appears to be working properly, self timer, the works! I'll also replace the top cover as the previous owner had engraved his SS numbrer on it in two places, with some other engravings elseware. I have two extra tops and bottoms in my scrap box, and will replace both top and bottom.

I also removed the front len' s elements, but cannot figure out how to get it apart to remove the fungus. I replaced the front elements with one from a lens I had in the box, but still would like to know how to get the front elements apart to save the one I removed.Anyone out there have any suggestions?

I still need to remove the top to give the viewfinder a good cleaning; thankfully, the focus appears to be right on at infinity. After I get this old warhorse functioning, I'll shoot a few pics and post them. I love these GSNs, [GTNs and MG-1s included] and I believe I've had at least one in my possession since 1970, when I was living in both Okinawa and mainland Japan [70-73]. From the outside condition of this latest acquisition, it's amazing that everything still works. They're one tough camera! If I can get this one cleaned and tuned in time, I may take it with me to Mongolia next month. Stayed tuned for further developments.;)
 
Taking the Yashica lens Apart

Taking the Yashica lens Apart

As you already know, you must remove the name ring, this will have two slits in it across from ea. other. After removal, you can use several differant types of lens tools to unscrew taking lens from shutter assembly, look on inter-net , Yashica guy has a excellant method for removal if you do not want to purchase a tool just f/removing a lens element, micro-tools has a most excellant selection of camera tools for the DIY guy. I found that after removing the front veiwing lens, using a dental dam to help grip the assembly, you can unscrew the lens apart, now some are easy and some take alittle work, but they will come apart. Now for the fun part, after cleaning and I suggest you use a cleaner that dries clear, you must remember the order, front to rear that the lens came apart, reassemble w/o touching the cleaned lens,LOL, screw the assembly back together and reinstall into shutter barrel. I have found that you must mark lens to insure you get back in right order, and its impossible to use you fingers to put lens glass back w/o touching, suggest you get one of the lens suction grips from micro-tools which allows you to put glass back w/o ever touching w/your fingers, or wear white cotton gloves while you do this. When you reassemble everything, just finger tighten, you do not have to torque tight. I have not found a lens yet that after the amount of years since mfg'd does not benefit from a complete tear down an cleaning. Unless the fungus has etched the glass, it is always to me a requirement to clean.:D
 
Front lens assembly

Front lens assembly

I was able to remove the front elements without too much trouble, and replaced it with a good unit from another junk camera. However, the problem is that the front lens element comes out as a solid piece with the two lens elements combined in a unit which I cannot see any way to separate them to get the fungus out. I'm sure the front lens unit is screwed together somehow, but right now I cann't see any way to get them apart.

The camera is now ready to fire up since I replaced the front lens unit, replaced the top and bottom, cleaned the viewfinder, replaced the seals, loaded it with Fuji 200, placed it in a bottom half of a Yashica case, shoulder strap, filter and lens hood, and tomorrow I'll fire off some shots tomorrow.

Thanks for your input.
 
Lens assembly

Lens assembly

You are correct, the lens comes out of the barrel as a unit, both front and rear element are combined into a single lens. I know it looks like they do not come apart, but they do, the front part of the lens un-screws from the rest of the group. I found this out by just taking a old lens and like we did when we were kids, tear apart to see how it works and or is put togeather. If you have a old, scratched or a lens etched by fungus, keep applying pressure to the front of the lens in a counter clock wise motion and it will un-screw. Do this so when the lens is ready to come out you have tag'd to know which side is the front of the lens, remove from assembly and you now have access to the inside of the front lens assembly glass, which allows you to clean between the glass lens in the front of the shutter. You also have the front of the shutter blades to get to and clean, albit, very, very carefully w/a cotton q-tip that has lighter fluid on bud. I purchased the Yashica Electro 35 repair manual from ebay and never looked back again to someone else to repair. The lens is easy, the POD, now there is some work and you seem to tackle as if easy, I believe if this is the case, you can with the right tools repair and or clean any part of these works of art.;)
 
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