I have been using Canon IXUS 130 for some years and it has been giving decent good photos and videos. Strangely, few days ago, whenever I use the telephoto zoom and take a picture, the picture is always overexposed and the over exposure is proportional to the telephoto zoom focal length. If I keep it at 24/28mm the photo is good.
This happens in Auto and Scene modes. I tried using manual settings in program mode but overexposure during zoom cannot be controlled. I then reset to factory settings and still the same issue. I find no solution to the problem whether I take a photo inside or outside.
I have had "under exposure" issue on my Canon DSLR EOS 20D a year back. Essentially, then, in auto mode, the camera used to pick high shutter speed or low aperture or a combination of both and pictures would be dark. I realized just a day before I had taken photos in slight drizzle / rainy weather, and let the camera lie for a few days and lo... some days later, this problem was solved on its own. I assumed that moisture and water could somehow tweak the camera's metering and auto aperture / shutter speed selection in the wrong way and now that the moisture would have evaporated, it works normally.
Could this be a similar situation? I am not sure because I did not use my point and shoot IXUS in any rainy weather.