This is what I've tried and found out so far...
When the back cover is open, the shutter release button fires normally. When the back cover of the camera is closed, the shutter release button will not fire and a red warning LED lights up in the upper right-hand corner of the view finder. I found a tiny pushable pin in the bottom crease where the back cover goes in when closed. While the cover was open I pressed the pushable pin with the tip of a pencil and the camera was fooled to thinking the back cover was closed - so the shutter release button fired fine (with LED warning light).
According to the Mamiya 6 manual - this warning LED lights up when pressing the shutter release button in the following cases:
a. when the lens mount is retracted
b. when light shield curtain is closed
c. film is not loaded
d. shutter has not been cocked (film advance lever has not been wound until it stops)
I tried cleaning the gold circuit connectors on both the lens and the lens mount. That didn't help.
I currently put in my 3rd test roll of film - and with the film in the camera the shutter release button still won't fire and the warning LED lights up just as it did without film in the camera.
There's a small hidden button on the right side of the camera which I never new about. According to the manual it's called an Emergency Winding-Stop Release Button. I read the description, but couldn't quite understand what its function is. Could this button possibly help me or be connected with my problem? Can someone explain exactly what it does? Here's the text from the manual:
If the batteries have been depleted - especially when the power on-off lever has been set to the OFF position during long exposures (at "B" ; 4 seconds or 2 seconds) - the winding-stop prevents the film from being wound. If this happens, push the emergency advance/stop release button with a pen or other pointed object as shown above. The advance/stop is then released, allowing the film to be wound. Please note that that articular frame will be poorly exposed. The emergency winding-stop release button should not be used for any other purposes.
Please help... I'm in the middle of a photography residency program in New York and I am lost without my favorite camera.