Olympus OM2 mirror goes up when I wind on

I have an Olympus OM2 which has developed an odd variation on the mirror lock-up issue.

First of all, having read a few threads like this, the batteries are new, and the mirror damping pads aren't sticky.

If I fire the shutter, all is OK (mirror comes back down), BUT as I wind on, the mirror goes back up, and stays there until I turn the shutter speed dial to B, and then it drops down again.

I have looked at what is happening with no lens attached, and as I wind on, the spring in the first picture gets stretched.
Sometimes this is all that happens, but most of the time, the lever/arm to the right of it in the picture moves too, and takes the mirror with it (second photo).

Any ideas on what the problem is?

Sounds like the mirror lock up safety feature is engaging.
Most frequently this occurs when the batteries or their connection are problematic. Are they silver oxide cells?

Yes, brand new silver oxide. Check light is glowing well.

The spring and lever in the first picture are the aperture stop-down actuator, and should not be moving when the camera is wound, only when it is fired. Even if the batteries are dead. This points to a mechanical issue rather than an electronic issue, IMO. Something is out of sync in the wind-fire sequence.

reddesert said:

The spring and lever in the first picture are the aperture stop-down actuator, and should not be moving when the camera is wound, only when it is fired. Even if the batteries are dead. This points to a mechanical issue rather than an electronic issue, IMO. Something is out of sync in the wind-fire sequence.

Click to expand...

Thanks for that. Yes, I can see where that lever fits in now, moving the aperture when a lens is attached. I have just had another go at firing & winding, and it will work OK for 3,4,5 times, and then it will move the mirror up and need a reset. Intermittent faults are the worst...

Mirror lever system (arming lever, retainer etc.) is visible when you remove the bottom plate, altough not fully. Best bet would be to remove the bottom plate and try to see what is going on during the correct sequence and what is wrong during the incorrect one. But I'm not sure it's an easy fix. Issues with the mirror often require you to relove the mirror box.