We are getting hoizpntal lines on all photos

As I wrote before for one other camera type you have the same problem with different solution on this case. Contact Canon service, is the best solution.
"My camera is 2 years old. 6 months ago horizontal lines began appearing in all pictures" The problem is not the sensor as the first solution has been posted, the real problem is connected with the flat cable inside lenses that is broken. You cannot replace it, you can raplace intere zoom. The problem is frequently on this type of camera and direct connected with camera frequent use. The fixed and automatic diaphragm do not work bacause broken flet is broken and the sensor is receiving too mach light. Take the camera, switch it on then light with a flashlight the lens, you see a diaphragm movement or hear a click on the lens, if not the flat wire is broken (means microcut inside flat invisible without a magnifying glass). Most time same problem is present with no image on the screen because diaphragm is completelly closed.

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