the shutter does not go fully down. The photos have a horizontal line on the top. Could you please advise?
It seems your shutter is wearing out. The line at the top of the frame indicates that the first curtain is never fully opening at the bottom of the sensor. (The image is inverted inside the camera - the top of the scene in the outside world is projected on the bottom of the sensor.)
Most people who have noted a problem such as yours find it gets progressively worse until one day the shutter does not work at all.