Displaying pictures from SD card

The screen needs replaced.You can them Ebay, and they
are not that difficult to do yourself. Good Luck

Does this occur only on the camera, or is it visible on your PC during PP operations ?

This is ccd imager chip problem, that chip will be replaced in your Canon A75 camera to get correct live view in camera mode to take pictures.
Canon offers free of cost ccd imager replacement for A75 and few other model, click Canon CCD Imager Advisory for details.

Hi!

Found some relevant info on how to adjust your video settings... You might want to give it a try!

Thanks! =)

4.12 PC Input Picture Adjustment
The Picture Adjust menu operates in the same
way for the PC Input as for the DTV / TV input in
section 4.2 for Backlight, Contrast, Brightness and
Color Temperature.
4.12.1 Auto Adjust
When the MENU button is pressed, the On Screen
Display (OSD) appears on the PICTURE ADJUST
page. Press the button to highlight the Auto
Adjust selection.
Press the button for the LCD HDTV to adjust to
the PC signal timing automatically.
4.12.2 H-SIZE
Press the button to highlight the H-Size selection.
Press the button to start adjusting the horizontal size of the picture. Use the or button to adjust
the horizontal size.
4.12.3 Horizontal Shift
Press the button to highlight the Horizontal Shift selection.
Press the button to start adjusting the horizontal position of the picture. Use the or button to
adjust the horizontal position.
4.12.4 Vertical Shift
Press the button to highlight the Vertical Shift selection.
Press the button to start adjusting the vertical position of the picture. Use the or button to adjust
the vertical position.
4.12.5 Fine Tune
Press the button to highlight the Fine Tune selection.
Press the button to start tuning the to the PC signal. Use the or button to adjust the tuning

4.14.1 Understanding Viewing Features
Your LCD HDTV features four viewing modes and Picture-In-Picture (PIP)/Picture-by-Picture (POP) mode.
You can switch viewing modes using the remote control.
4.14.2 Viewing Modes
Normal Mode
The original 4:3 aspect ratio (1.33:1 source) is preserved, so black bars are
added to the left and right of the display image. Standard TV broadcasts are
displayed with a 4:3 Aspect Ratio. Movies in 4:3 Aspect Ratio may be referred
to as pan-and-scan or full frame. These movies were originally filmed in 16:9
(widescreen), and then modified to fit a traditional TV screen (4:3).
Wide Mode
When watching a standard broadcast or full-frame movie in this mode,
the display image is stretched proportionately to fill the TV screen.
When watching a widescreen (1.78:1 source) program or movie, the
display image fills the TV screen. If you are watching a widescreen
(1.85:1 or 2.35:1 source) program or movie, there will still be black
bars at the top and bottom.
Zoom Mode
When watching a widescreen (1.78:1, 1.85:1, or 2.35:1 source)
program or movie, the display image is zoomed proportionally to fill the
width of the screen. The top and bottom are cut off to remove most of
the source material’s black bars. This mode is good for programs or
movies with sub-titles.
Panoramic Mode
When watching a standard broadcast or full frame movie in this mode,
the 4:3 Aspect Ratio (1.33:1 source) display image is stretched
horizontally on the left and right sides to fill the TV screen. The center
of the image is not stretched.

Note: Viewing modes are saved based on input. For example, you lasted watched a DVD in widescreen
mode and then watched TV in standard mode. When you switch back to DVD input, the viewing mode
will return to widescreen.

How are you transferring pictures with the other cards? Are you using a USB cable and plugging the camera into the PC? If not, how are you doing it. Let me know the answer... I have some suggestions for you.
Regards,
Char1ieJ

PS - Please don't rate this answer just yet. We still have a step or two to go before resolving your issue.

Its known problem of CCD Imager in Canon A70 camera and CCD Imager needs to be replaced.
Canon offers Free of Cost repair for such problem in A70 model.
Click Canon CCD Advisory for details.

The most common cause of this is a failed image sensor. Usually the playback mode will let you view pictures taken before the issue happened just fine and you will also be able to view the menu system just fine. When viewing the screen in an image taking mode, however, there is typically discolorations, horizontal or vertical lines, image bluring or distortions, or simply a black screen.

This situation, if caused by the image sensor, has to serviced and cannot be fixed by the user. If you are within your one year warranty and no user damage has been done to the camera, the camera will be fixed at no charge. If beyond the 12 month period however the customer may opt to have the unit repaired at a cost or take advantage of the Canon Loyalty Program and upgrade to refurbished S3 IS at an alternate discounted price.

Hope this helps.

Sincerely,
HeavyDLB

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 shutter leaf dropping into the image. however, they are usually horizontal and more likely to manifest when in landscape mode. (horizontal, normal)
try using flash pointed up to ceiling.
also, could need to check for auto sync speed setting. usually 1/125 to 1/60. if its off, it could be catching the shutter in the wrong place.
check manual for settings for using flash.
mark

CCD fault.