Without film inside the test button and shutter give plausible feedback - green light blinks when dark, stays lit when more light available and I can see different shutter speed selected with different light available.
Problems start when I insert the film cartridge (I only have one type of film - Lomography CN tiger 200). When the film cartridge is inserted into the body the test button will only do a short blink when pressed (or glow with lower intensity if I keep test button half pressed), shutter will fire but not close and film will not advance.
I've located the problem. If I push the "ISO sensing pin" all the way in the problems start. But I have to press down on the pin really hard (with my nail or a hard object). If I press on it with my finger I can't push it in far enough to cause the problems. It's probably a question of a fraction of a mm... So, if I don't press on the pin the camera thinks there is ISO 400 film in the camera, if I press on the pin camera thinks there is ISO 100 film present and then if I press it in all the way camera stops functioning.
Anyone had a problem like this?
If I put a piece of tape on the cartridge rail, so that the pin can't sink in too much, the problem goes away, but I'm thinking this is not the best solution since film will now not sit in correct position.
I'm thinking of sanding a bit off of that pin although it will be hard to do that without disassembly. And, of course, the question remains, why/how does the pin pushed all the way in cause the camera to stop functioning?