My Canon Power Shot A75 will not take a picture, nothing is visible on screen and nothing comes out if I try to take a picture. Play back works.

Please see the following comment:

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 known problem of bad ccd imager chip in Canon A75 camera and ccd imager will be replaced to get correct live view image.
Canon offers free of cost repair for A75 camera for bad ccd imager problem, click Canon CCD Imager Advisory for details.

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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

Its bad ccd imager in camera and this part will be replaced.
Canon will repair Free of Cost A75 camera as per announced scheme.
Click Canon CCD Imager Advisory for details.

If the camera comes, the lens comes out, but no display, push the DISP button on the back. If it will display previously recorded images, but not take new ones, the CCD could be repaired free by Canon. Go here for more details: http://www.imaging-resource.com/badccds.html

Hello Dear,
This is a problem with the Camera CCD unit, u r requested to carry the Camera to the Canon Care Centre and your job will be done free of cost.
Wram Regards,
Manoj Joseph
+91 9352008418

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

Yes they'll fix this for free, see:
http://camerarepair.blogspot.com/2007/11/canon-digital-cameras-showing-black.html

Note that Canon should fix this for you free Worldwide. Sorry, but I don't understand French. But here's a starting point for your search for repair help in France:
http://www.canon.fr/Support/index.asp