Whitish picture with horizontal lines

This sounds like it might be a defective CCD imager. If so, Canon should fix this for you for free, including free shipping both ways. This is regardless of your camera's warranty status. Please check this link for more info.

Applicable cameras include: A40, A60, A70, A75, A80, A85, A95, A300, A310, S1 IS, S60, S200, S230, S330, S400, S410, S500, SD100, SD110, IXUS V2/300/400/430/500, IXY Digital 30/30a/200a/300a/D320/400/ 450/500

This is the fix for the Main board repair :
Locate IC 32 small 8 pin surface mount near top of Main Board and remove. Short pin 2 to pin 5. (pin 5 through 8 are together and pin 2 and 4 are together)
You will need a good TV Tech to do this for you.

Sorry. Your screen dies.

What is the make and model of the camera? It sounds defective. I work for a digital camera manufacturer and we have the same thing. Probably will need to be replaced.

For both of you, this sounds like it might be a defective CCD imager. If so, Canon should fix this for you for free, including free shipping both ways. This is regardless of your camera's warranty status. Please check the following two links for more info:

http://camerarepair.blogspot.com/2007/11/canon-digital-cameras-showing-black.html

http://www.usa.canon.com/consumer/controller?act=PgComSmModDisplayAct&fcategoryid=225&modelid=13390&keycode=2112&id=29819

Applicable cameras include:
A40, A60, A70, A75, A80, A85, A95, A300, A310, S1 IS, S60, S200, S230, S330, S400, S410, S500, SD100, SD110, IXUS V2/300/400/430/500, IXY Digital 200a/300a/400/450/500

Sounds like a bad component on the video board. These days, TV techs just swap out boards for whole new ones.

If you get a blank LCD, dimly lightened by a whitish back light, then the LCD display eis either faulty, badly connected, or the ribbon connector to LCD is defective.
The camera must be taken apart, ribbon cable tested, and eventually replaced and adjusted.
If all contacts on ribbon cable return continuity (cable is fine), then LCD is faulty, and must be replaced.
Althought the job is not too difficult, an user without experience may damage the camera in attempting this repair.
My first suggestion is always taking the unit to a camera shop.

CCD is weak

This sounds like it might be a defective CCD imager. If so, Canon should fix this for you for free, including free shipping both ways. This is regardless of your camera's warranty status. Please check the following two links for more info:

http://camerarepair.blogspot.com/2007/11/canon-digital-cameras-showing-black.html

http://www.usa.canon.com/consumer/controller?act=PgComSmModDisplayAct&fcategoryid=225&modelid=13390&keycode=2112&id=29819

Applicable cameras include:
A40, A60, A70, A75, A80, A85, A95, A300, A310, S1 IS, S60, S200, S230, S330, S400, S410, S500, SD100, SD110, IXUS V2/300/400/430/500, IXY Digital 200a/300a/400/450/500