Mamiya 80mm N/L Problems

Hi Forum,

I've got a problem with my Mamiya 80mm f2.8 N/L lens on my 645 Pro TL. Recently I took a shot (it was quite cold outside) and suddenly the lens was closed. Looking into the lens the shutter blades are not open (see also attached pic).

I never used the leaf shutter of the lens only the one of the camera body. I checked the manual and it says: Turn the M/A selector to M and cock the manual shutter. When this is done, according to the manual, the shutter blades shall be completely open; but they are not .

I checked all other options in the manual but with no luck. Is the lens done?

Maybe someone still know how to open the lens. Would be a pity to throw it away

Thanks you!