my previous message (draining batteries on my D4s) seemed to have been solved by using a different charger (I still have to let exchange the charger).
But now I notice the following problem: If my 24-70 f / 2.8 VR lens is attached to the D4S and I take a picture with a longer shutter speed (for example, 6 seconds) I hear an echo(/buzz) when taking the photo. When I use a 70-300mm lens with the same shutter speed, I do not hear that echo.
Another thing I noticed is when I turn my camera down to see the photographs, the display (while looking at the image) shuts down from time to time (the camera remains on). I have that problem some time going but thought it was me touching some button on the frontside of the camera, but I've reassured myself I'm not pushing any button while looking at my pictures.
FYI: my D4s runs on the latest firmware.
Can someone help me or tell what causes these problems?