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Canonized_joe
Tinkerer Username: Canonized_joe
Post Number: 8 Registered: 10-2006
Rating: N/A Votes: 0 (Vote!) | Posted on Sunday, January 28, 2007 - 10:26 am: |
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recent acquisition, Canon AE-1 body, has a problem I would appreciate advise on. When activated, the meter always pegs the needle full-down and the LED there flashes. I have seen reference to this problem on this and other forums. The stop-down lever seems to be the culprit (I may have depressd it on 1st examination). Also, mounting the lens with it not set to "A" can produce it. I tried several different FD lens, battery out of camera, "rocking" the aperture to its most open setting (ala older nikons)-problem remains. the signal pins, camera & lenses appear in place & "springy"; I also verified that the "red dot" uncovered by stopping down was not visible. Anyone know of another cause for this phenom? btw the focus screen is a little dark & scratchy. Thanks in advance Joe |
Krp
Tinkerer Username: Krp
Post Number: 23 Registered: 07-2006
Rating: N/A Votes: 0 (Vote!) | Posted on Sunday, January 28, 2007 - 02:25 pm: |
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Under the top cover, there is a tungsten wire that runs from the speed dial to the brush set on the rewind side of the camera. It is likely broken. You can confirm this by removing the rewind knob and the plastic cover plate below it. The metal dial under there should rotate as you change the speed or the asa settings. If it doesn't move, the wire needs replaced |
Canonized_joe
Tinkerer Username: Canonized_joe
Post Number: 9 Registered: 10-2006
Rating: N/A Votes: 0 (Vote!) | Posted on Sunday, January 28, 2007 - 04:35 pm: |
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Thanks Krp. I have never had a top cover off, but this is a decent candidate = low $$ and so-so condition. I have Rick Oleson's notes & I recall that he has a diagram for top removal (I realize that your suggestion is a short-cut to diagnose, not cover removal). After I stir up the courage I will probably need to get a few tools (spanner, etc). Question: is the tungsten wire a soldered connection or part of a cable drive system? Does it need to be tungsten? As an aside, I saw reference to lubricating the mirror box "Squeak" from the bottom. Does anyone know the particulars? Rick's method goes thru the top. Thanks all! |
Glenn
Tinkerer Username: Glenn
Post Number: 128 Registered: 07-2006
Rating: N/A Votes: 0 (Vote!) | Posted on Sunday, January 28, 2007 - 07:35 pm: |
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The tungsten wire is part of a drive system. Repairs can be made using fine metal cored fishing trace line. Search the archive for discussions on this subject. Do not use the 'through the bottom' method. The cure for the 'squeak' is ONE 1mm diameter drop of oil, placed on the end of axle that supports the flywheel of the mirror damper. You only have to lubricate the sleeve bearing in the flywheel and its associated pinion. The rest of the gears are Delrin and require no lubrication. Lubricating through the bottom is the quickest way of getting oil on the shutter blinds and generally messing the interior up. |
Canonized_joe
Tinkerer Username: Canonized_joe
Post Number: 10 Registered: 10-2006
Rating: N/A Votes: 0 (Vote!) | Posted on Sunday, January 28, 2007 - 07:50 pm: |
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Thanks Glenn. I am testing the wire as suggested by Krp now & have printed Rick's pertinent illustrations to keep handy. It really is tungsten wire - interesting! I do not know, yet, what "metal cored fishing trace line" is but several fishing shops are in the area in case I need some. Thanks guys |
Canonized_joe
Tinkerer Username: Canonized_joe
Post Number: 11 Registered: 10-2006
Rating: N/A Votes: 0 (Vote!) | Posted on Sunday, February 04, 2007 - 02:24 pm: |
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Attn: Krp. A little more advice pls. I removed the rewind knob & the metal dial does rotate with the SS/ASA knob at all settings. I am not certain that the "conductor" shown on Rick O's diagram is aligned properly with the PC board as I have not yet removed the top cover. I installed a battery & checked the meter at all ss/asa setting - still bottoms out on all. I tried it on "manual", setting the f-stops on the lens, & it appears that the shutter speeds are reasonable & the aperture stops down. Any further thoughts greatly appreciated. Joe |
Krp
Tinkerer Username: Krp
Post Number: 25 Registered: 07-2006
Rating: N/A Votes: 0 (Vote!) | Posted on Sunday, February 04, 2007 - 03:26 pm: |
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Ouch. the next likely cause of the meter problem is electronic. You may have a dead IC chip. I'm afraid that surface mount chip replacement is not practical. Canon used to sell the IC's separately, but those parts are no longer available. kevin |