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Mndean
Tinkerer
Username: Mndean
Post Number: 8
Registered: 08-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, August 20, 2007 - 06:45 pm: | 
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I got a Minolta SRT with an MC Rokkor-PF 58/1.4 lens, and it has a very stiff aperture ring which will not turn without considerable effort. The blades are not at all oily or sticky, and when using the stopdown lever, the blades close and snap back open very easily as they should. Is there anyone who has seen this kind of problem and can guide me to a fix? |
Rick_oleson
Tinkerer
Username: Rick_oleson
Post Number: 347
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, August 20, 2007 - 07:35 pm: |
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It sounds like the problem is in the ring itself. this can be removed from the back, but it is a little tricky: in the back of the mount, there are 8 screws, alternately long and short. Pull out 2 adjacent screws to see which ones are the long ones, then put the short one back and remove ONLY the 4 long screws. Sandwiched in the rear mount is a ball bearing assembly that is eager to go flying around your house if you let it out...
Once you have the mount off, the aperture ring can be lifted off for cleaning and relubrication. Watch out for the single steel ball and spring that provides the click stops, it will be loose when you remove the ring. |
Mndean
Tinkerer
Username: Mndean
Post Number: 9
Registered: 08-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, August 20, 2007 - 08:35 pm: |
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Thanks, Rick! I'm glad I asked, because I found a disassembly chart for the lens and if I'd followed that I'd have made far more work for myself. |
Mndean
Tinkerer
Username: Mndean
Post Number: 11
Registered: 08-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, August 23, 2007 - 05:15 pm: |
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What would be the best choice for a lubricant around the ring? |
Rick_oleson
Tinkerer
Username: Rick_oleson
Post Number: 351
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, August 23, 2007 - 06:57 pm: |
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I use white lithium grease for areas like that, it pretty much stays where you put it. |
Mndean
Tinkerer
Username: Mndean
Post Number: 12
Registered: 08-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, August 24, 2007 - 12:08 pm: |
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Thanks, Rick! It's all back together and working smoothly. |
