Suddenly all my pictures are coming out looking overexposed, almpst white, some with streaks. I have a Canon PowerShot A540. No problems for three years.

The shutter flex cable inside the lens is broken. Happens to all cameras from Canon A4xx series. At day the images will be overexposed with horizontal lines on it, but it could look better at dark / night. The FLEX has to be replaced. Canon doesn't supply new flex cables for these, but there are some cheap copies on ebay. But as these brake very often, I wouldn't suggest you investing money in this camera, because it will brake again sooner or later.

Either aperture ring is jammed or CCD is bad.
Needs service.

Hi there its a chance of sersor damaged. He not able to read the light. Thats why outside image are over exposed. I suggest you visit service center for check or repair the lens sensor.Thanks.

hi user,

either try puttin iso in auto mode or put it below 1000 if u r in day lite and adjust ur exolrsure setting which will even help u not getting over exposed

Change the exposure/ISO through settings.
This is the cause for over exposed images.

The camera is defective. But as you've only had the camera three months it still is under warranty. Canon is usually very responsive to these type of problems and will bend over backwards to make things right (probably the most responsive of the camera companies).

Call 1-800-OK-CANON to resolve this issue.

If you are looking canon A540 user manual then get it from Canon Support.
If model number is different, let me know.

I have similar problem.highlights overexposed,with streaks of pixels running vertically.overall pinkish hue

This may be a ccd problem.
See this link.
http://www.usa.canon.com/consumer/controller?act=PgComSmModDisplayAct&keycode=2112&fcategoryid=221&modelid=8776

To view the pictures on the computer, remove the card from the battery compartment and put it in a card reader connected to your computer.