Hello all, I'm having an issue with a newly-bought Olympus OM-1 35mm camera, but I've had no luck finding a solution to it online. If anyone has experience with these cameras and could offer any help, I would massively appreciate it! (In what follows, part numbers refer to the Olympus OM-1 Service Manual.)
In brief: the Mirror Hooking Lever (CA8419) is releasing the Mirror Charging Lever (CA8412) prematurely, releasing the tension on the spring responsible for firing the mirror when the shutter button is pressed. Generally this premature release happens just before the film advance lever's action is completed (see video), but sometimes it happens as the shutter butter begins to be depressed. The result is that the frame is advanced and the shutter is cocked, but because the mirror isn't cocked, neither it nor the shutter will fire and the camera is rendered inoperable.
I can restore function by removing the bottom plate and manually pushing the Mirror Charging Lever down using the KM Lever (CA8865), which seems to successfully engage the mirror hook every time. But after anywhere from 1 to 60 shots, the problem occurs again.
(Proper function: Actioning the film advance lever primes the mirror as follows. CA8865 (KM Lever) is pushed by a cam and turns counter-clockwise, causing it to push CA8412 (M Charging Lever) toward the front of the camera body. Inside the body, spring CA8448 is now tensioned. Part CA8419 (M Hooking Lever) holds the M Charging Lever in place, retaining the tension in the spring (mirror is cocked). After that, depressing the shutter button will cause part CA8862 (KL Plate) to move laterally, pushing Unidentified Claw Part (I can't find this in the manual). If the mirror is cocked, this initiates mirror movement; when the mirror is fully lifted, the shutter is triggered.)
Has anyone ever encountered this? I'm a bit flummoxed! I got this camera very cheaply (<£50) and in my current situation can't afford to pay for a repair, so I'm keen to fix it myself. Any insights would be a godsend.
In brief: the Mirror Hooking Lever (CA8419) is releasing the Mirror Charging Lever (CA8412) prematurely, releasing the tension on the spring responsible for firing the mirror when the shutter button is pressed. Generally this premature release happens just before the film advance lever's action is completed (see video), but sometimes it happens as the shutter butter begins to be depressed. The result is that the frame is advanced and the shutter is cocked, but because the mirror isn't cocked, neither it nor the shutter will fire and the camera is rendered inoperable.
I can restore function by removing the bottom plate and manually pushing the Mirror Charging Lever down using the KM Lever (CA8865), which seems to successfully engage the mirror hook every time. But after anywhere from 1 to 60 shots, the problem occurs again.
(Proper function: Actioning the film advance lever primes the mirror as follows. CA8865 (KM Lever) is pushed by a cam and turns counter-clockwise, causing it to push CA8412 (M Charging Lever) toward the front of the camera body. Inside the body, spring CA8448 is now tensioned. Part CA8419 (M Hooking Lever) holds the M Charging Lever in place, retaining the tension in the spring (mirror is cocked). After that, depressing the shutter button will cause part CA8862 (KL Plate) to move laterally, pushing Unidentified Claw Part (I can't find this in the manual). If the mirror is cocked, this initiates mirror movement; when the mirror is fully lifted, the shutter is triggered.)
Has anyone ever encountered this? I'm a bit flummoxed! I got this camera very cheaply (<£50) and in my current situation can't afford to pay for a repair, so I'm keen to fix it myself. Any insights would be a godsend.
Last edited:
