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Kai
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, July 18, 2005 - 07:40 am: | 
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Hi Everyone!
Got an OM-1. The meter doesn´t react on movin the aperture sensing ring.
I think the aperture-sensing-Ring-WIRE is broken!
Any idea how to fix this? Where can I get a new wire or what can I use instead. What else can be the fault if the whire is faultless.
And how to reassemble the whole Camera afterwards?
Best wishes from Germany an many many many thanks for your help!
Kai |
Robert
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, July 18, 2005 - 03:04 pm: |
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Before you attack the aperture sensing stuff, check that the battery box wires are connected and passing power to the camera electronics. And see that a metal screw has not been substituted for the insulating original plastic screw securing the battery box. |
rick oleson
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, July 18, 2005 - 04:37 pm: |
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Also, before looking into the aperture ring cord, determine whether you have an early or late model OM1: when you remove the lens, in the early model you can see a little round cam thing on the black panel just above the focusing screen. In later ones this panel is blank. The procedure for servicing these two types is very different. |
Kai
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, July 19, 2005 - 04:34 am: |
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Power works fine, reaction on changing the time and the ISO settings...
Wich model. don´t know..I´ll have a look.
Think that the cord/string is broken. Can I glue it / wich glue??
Do I have to replace it? Where to get an original part??
Or can I just use some string of the same thickness? |
Winfried
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, July 19, 2005 - 07:26 am: |
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You can use a wire of similar diameter. Wires used in cameras have very small diameter. You can rip off a strand (single wire) out of a broken computer cable. Cut the outer isolation layer with a knife. Remove the shield (either metal foil or woven blank wires) and you have wires of a dozen or so different colors.
Wires in cameras usually require careful soldering. If you don't have experience in precise soldering let it someone do for you. With a non-temperature regulated soldering iron you will destroy more than you will repair.
However, I don't think it is the wire. Pretty often the contacts where the coil wires of the galvanometer are soldered to the terminals are broken. This damage hardly can be repaired and would require VERY careful soldering. |
Clint
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, July 22, 2005 - 07:58 pm: |
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This is not a simple problem. When the coupling ring inside the lens mount is turned, it will either move a cam follower (on older versions) or a gear assembly (on later versions). In either case, those mechanisms at the top of the coupling ring (under the cover there) will pull a nylon string that is attached to a pulley on the underside of the meter frame, mechanically moving the meter to physically position it.
It's possible that the nylon string on the underside of the meter housing has slipped off the pulley. With the top cover off, you should be able to see the meter turning as you operate the coupling ring -- if not, that's what I'd check first.
On earlier models, you will see a roller at the top of the coupling ring that should ride against a cam that's part of the coupling ring. If you have one of these early models, you will have to first remove the hot shoe's "roll bar", then the prism before you can remove the frame that holds the meter. Then you can remove the screws that hold the plastic frame containing the meter, eyepiece, and circuit board, and carefully lift the whole assembly up off the camera. The string that couples the meter to the coupling ring should still be attached. This frame is likely to be quite fragile due to it's age.
The string should make two turns around the pulley before replacing the frame. Be careful that the string is not pinched between the plastic frame and metal of the body when replacing! Let the pully "eat" the string as you lower the frame into place -- if it slips off the pulley, you'll have to start over. Make sure the meter moves freely as you operate the coupling ring before reinstalling the screws.
On later versions, with no roller at the top of the coupling ring, it's much easier to remove the meter as you do not have to remove the prism first. The meter housing is separate from the eyepiece and the circuit board, and can be removed by unscrewing only two screws. Be careful when lifting the housing out, though, as you don't want to bend the meter needle. Tilt the top of the meter in towards the prism as you lift it up and away from the prism to clear the needle.
On these versions, there will only be _one_ turn of string on the pulley before reinserting. And if the pulley on the bottom of the meter is black plastic, you're in trouble -- the plastic ones were prone to sticking, a primary cause for the string jumping off the pulley. It was replaced with a brass one to correct the problem.
Again, be sure the string is not between the plastic meter housing and the metal of the body as you lower the housing back into place. Tilt the top of the meter in toward the prism to avoid the meter needle as you slip it into place. And again, be sure the meter moves as you operate the coupling ring before replacing the screw -- you _don't_ want to cut the string!
If the string is broken already, you will want to harvest a replacement part from the same version body. First, that string's length is critical of course, but more importantly it is almost impossible to replace that string so that it works properly. Where it attaches at the top of the coupling ring is extremely delicate no matter which version you have.
If that's not it, let me know. |
Kai
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, July 25, 2005 - 12:47 am: |
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Thanks a lot for your advices, I'll try to find the problem next weekend!!!
Thank you!
Regards,
kai |
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