My Canon EOS 30 has stopped working properly...?

If ALL images, under ALL circumstances, are over exposed, then your camera probably needs repair unless you have set a consistent exposure compensation by accident in the camera settings.

My best first approach if some pictures are okay (exposed the way you are used to and expect) is to take the lens off the camera, wipe off the contacts with a micro-fibre cloth and put it back on. Then try it.

A quick and dirty test is to fill the frame with something white under even light in Auto and then photograph something very black. On your histogram, there should be a cluster right around the middel of the histogram looking pretty much the same for both exposures. You camera should try and make both exposures the same level of gray.

Do the same with Program mode, making sure that the exposure is not over or under as you see it in the viewfinder.

If that doesn't work, then take it to a camera store and have them check it out.

If the camera store says its fine, then you have a little experimentation to do.

I have never used auto or any of the mode settings on my camera, so I had to go fire mine up and take some pics. I can get my camera to overexpose or underexpose pretty much at will by choosing the right subjects.

The more automatic control your camera uses, the more problematic shooting a good picture becomes. In Auto, the camera is going to do everything. It sets the metering mode, ISO, shutter speed, aperture and figures out what you are focusing on. Depending on the scene, the camera can be tricked into over or under exposure. It may make assumptions that won't work for the actual scene. It could be that shots you have recently taken are not typical of shots you took before where the camera 'worked'. Look to see if they are significantly different (backlit, time of day, scene contrast between light and dark and amount of light area to dark areas, etc.). If you see a pattern, you have found the circumstances under which Auto won't provide a good exposure. Auto uses Evaluative Metering on the Canons. Switch to Program and;

If you just use Program and the default Evaluative Metering, you will get the same results as Auto. Same type of exposure under the same circumstances. You have three metering types to choose from and they are useful under different metering circumstances. In Program mode, choosing the right metering may make the difference.

With enough experience, you will find out the exposure characteristics for different scene situations and can compensate accordingly.

Part of using a camera like the 30D is the assumption by the manufacturer that the user knows enough about photography and how to use the controls the camera provides to get the images they want. The Auto function and Program modes in these cameras is not as good, frankly, as it is in many point and shoot cameras.

Without seeing pictures it's hard to say what the problem is, but it could very well be your assumptions about how the camera is metering and determining exposure are not what the camera is doing.

Vance

have you set the exposure properly? Try to read the manual and read what's the status of your camera (especially the part where it indicates shutter speed).