From your description I assume that you can see the menu. Are you able to see previously taken photos (before the problem) in the LCD screen?
To set a reference point, hard reset the camera by following the instructions below.
Remove the main batteries and the memory card. Remove the Time/Date battery (shown in the attached photos). Press the on/off switch once and then allow the camera to sit idle for 10 minutes. Press the on/off switch once more, then, insert the Time/Date battery and main batteries only, not the memory card and power the camera up. You will need to reset the time and date and any other custom settings.
If the reset did not restore normal operation, then, unfortunately what you have described indicates that there is a problem with the ccd or the connection to it, and while your camera is not on the current list of Canon cameras for possible free repair, the information at the link below explains the symptom and since more and more models have the identical problem and your camera was made around the same time: click on or copy and paste the link into your browser
Please keep in mind that my diagnosis & solutions provided are directly dependent on the accuracy of your description of the problem. As with any "do it yourself" fixes, success is a "team effort", since I can't see or touch the camera, and relies on the customer's manual dexterity and ability to follow the instructions well.
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