I am having a problem with one of my 645 Supers. I issue is that, when I advance a frame the shutter continually releases. The crank/winder (tried it with both) trips the shutter every go-round. This is only in manual override mode. When I set it to regular shooting the crank releases the shutter and the shutter never recovers (the mirror stays up). I have never had this problem before (with other bodies), so any help would be great. Thanks! Chris
im having shutter problems with mine as well, it will not release at all, but when i took the back off, i could fire the shuter fine. when the back goes on it will not fire.
Try a new Silver Oxide battery--your battery may be low, but still make the meter read and the check light may also still glow.
DO NOT use an alkaline or any other kind of battery. They
weaken at a different rate than silver batteries. Also be sure to replace them at least once a year.
The shutter is controled by an electro magnet and a weak batt can can cause the symptoms you are having.