DSLR camera issue with manual shutter speed / aperture settings - not enough exposure?

When you put the camera in auto it also sets the ISO - are you setting the ISO to the same value? You haven't told us how bright the light is and what exposure you are using so it is hard to judge. Go outdoors on a bright sunny day. Manual mode - Set ISO to 100, shutter to 1/00, aperture to f/16. If it isn't bright and sunny try f/8 or f/5.6. How do they look?

1) learn to balance ISO, shutter speed and lens aperture here http://camerasim.com/camera-simulator/ 2) Dark shows underexposure 3) if you look at the light meter in the viewfinder, you will see that the underexposure is shown there.

When you said you used the settings that were on auto - I cannot figure if you replicated the ISO as well as the shutter speed and aperture, or did you just use the shutter speed and aperture settings? If you compare the shutter speed, aperture, and ISO with the manual setting, then the exposure should be the same. And you also need to make sure the focal length of the zoom lens is not disturbed, because with your kit lens, the light entering the camera will change with the zoom position.

What's the EXIF data for the fully Auto photo(s)? Are you sure the ISO is 100 with those? There really shouldn't be any difference between the different exposure modes if the aperture and shutter speeds are the same in them all, at the same ISO.

It depends on the limits of the camera. If you are setting the shutter speed and the camera is choosing the aperture, the aperture is limited entity. If the image is fine when on automatic, it is unlikely the camera is broken. I am not familiar with that model, but most Nikon DSLR's have a TTL light meter. Check out these web sites for more information regarding the relationship between ISO, aperture, and shutter speed. All of those are closely related and impact each other. http://www.cambridgeincolour.com/ http://www.digitalcameraworld.com/ Best wishes.