help with OM-2n advance lever problem

[michael_white4]

I've acquired an OM-2n which has a problem with the advance shaft.

It appears that this camera may have been dropped at one point in time

and landed on the hot shoe causing a minor dent in the prism housing.

Looking at the rear of the camera, the part of the top cover to the right of

the prism was angled very slightly upward, probably a result of its accident.

 

I was able to remove the top cover, but while removing the advance shaft nut

(the one below the advance lever) it was jammed very tightly on the shaft

and the shaft was turning while I was loosening the nut. I had to

hold the shaft while loosening the nut. As I was loosening the nut I heard a

sound like a spring losing its tension. After removing the cover, its obvious

there is something amiss in the shaft. The entire top section of the

shaft, frame indicator, large coiled spring is very wobbly, almost as if this is

supposed to be attached to something below. The spring is still in place, and

under some tension.

 

Before starting to disassemble I thought I would ask if anyone has seen this

type of problem and could offer any advice about what could have happened and

how to correct this. I have three OM's and have successfully removed the top

cover on

the other two and cleaned the prism foam. This is the only one who's prism

was unaffected by the foam. But now I need to solve this advance problem.

Thanks in advance.

[john_hermanson2]

It sounds like part of the wind mechanism plate (2 steel parts stamped together at the factory) have broken apart. Top plate of wind mechanism would have to be replaced. John, www.zuiko.com

[michael_white4]

Thanks for the reply :-) I guess that would be ZJ1290

(or CA9186) FC base plate. Must have been quite an impact

to break those pieces apart. Looks fairly straightforward

to remove. Are there any tricks to retensioning the

spring CA8774 under that plate ? Is this the advance lever

return spring ? I have a parts OM-10 but the plate looks

slightly different.

[john_hermanson2]

You will have to use a ZJ1290 from an OM-1, 1N, or 2. All other OM bodies are non compatible. Re-tensioning spring is very straightforward. Be careful when removing wind shaft from body. Lower tip sits in a small plastic bushing which fits inside the metal bushing at the bottom inside the takeup spool. Metal bushing is actually underside of the battery box. usually, when pulling wind shaft out, plastic piece comes out too and gets lodged inside takeup spool. IF the plastic bushing falls out or is not used, tip of wind shaft will touch metal part and short the batteries out. John, www.zuiko.com

[michael_white4]

Thanks , that was it ! Those two pieces are separated.

I removed the frame counter ring and spring, and was able to

push the pieces back together but they wont stay , as its a

very loose fit. So I'm wondering if these were ever really press fit together. There does appear to be a brown residue at the junction,

could be glue? or maybe just corrosion.....

 

Maybe it would be possible to reattach these two back together somehow. Looking at the way the spring attaches into a small

hole in the upper piece, I think the rotational position would be

somewhat critical as that determines the amount of tension on the spring when the advance lever is fully retracted.

 

Probably not the ideal solution ,need to think about this

some more , and maybe pickup a parts OM1 or OM2 from eBay.....

[dshombert]

I feel that somebody should point out that John Hermanson makes his living servicing Olympus cameras. A lesser person in that capacity would probably not have been so willing to volunteer specialized technical advice to somebody doing a job on their own. John, you're a class act.

[john_hermanson2]

The parts are stamped together at the factory, likely under tons of pressure. I'd guess it was caused by the already mentioned impact damage. Once out, you won't be able to get it back together. In the last 20 years I can remember only two or three cases where this unit has come apart. For $10 + shipping, I could send you a used one, with counter parts attached. John, www.zuiko.com

[michael_white4]

Thanks again for the advice and offer John, I've sent you an email about this.

[michael_white4]

Thanks to John I was able to get this OM-2N working again !

John sent me the replacement part , an entire assembly that

I was able to drop in without much disassembly. It took me

awhile to figure out how to install it... but I finally did,

and it's working !

 

Thanks again John !