No image appears on LCD monitor once turned on.

This appears to be a deeper problem than can be fixed with advice on here. I suggest you take it for a professional repair. Check the repair estimate with the value of the camera.

The Display button toggles the information shown on the LCD (or turns it off entirely). Make sure you haven't inadvertently pressed it and turned off the display. It works as follows:

Press once for Normal view in LCD viewfinder
Press twice to turn on Rule of Thirds grid lines
Press three times to turn off LCD display
Press and hold 1 sec. to decrease/increase LCD brightness

The Display button toggles the information shown on the LCD (or turns it off entirely). Make sure you haven't inadvertently pressed it and turned off the display. It works as follows:

Press once for Normal view in LCD viewfinder
Press twice to turn on Rule of Thirds grid lines
Press three times to turn off LCD display
Press and hold 1 sec. to decrease/increase LCD brightness

This link may help you :

Canon Camera ZR65 MC

Most common failures in the LCD monitors are bad capacitors (bulging top/seal or leaking) in the power supply, failed inverter circuits (blown fuse, shorted transistors, shorted/open transformers), bad lamps (poor solder connections or worn out lamps). You will need to open it up and inspect the inside, see example of failed monitors to get some ideas what to look for: http://s807.photobucket.com/home/budm/allalbums
Post back what you see inside so we can guide you further and it will help out other people in the future also.
http://www.badcaps.net
http://en.wikipedia.org/wiki/Capacitor_plague

I can help you fix the BUSY Error or Error 99 of your Canon EOS Rebel XS .

Installation of this Canon EOS Rebel XS firmware version 1.06 update will solve these problems:

1. Some cameras may exhibit a phenomenon in which the LCD monitor does not display, the shutter does not release, and the BUSY indication remains lit in the viewfinder.
2. The message, "Err 99 Shooting is not possible. Turn the power switch to<OFF> and <ON> again or re-install the battery", appears on the camera's LCD monitor, and after the above operation is carried out,the LCD monitor displays in a language that is different from the actual language setting.

See the firmware instructions and download the firmware upgrade by following these Fixya Tips :

1. Follow this link to download a pdf version of the firmware installation instruction guide.
2. Follow this link to download the Windows Version of the Canon EOS Rebel XS / Canon EOS 1000D firmware version 1.06 update.
3. Follow this link to download the MAC version of the Canon EOS Rebel XS / Canon EOS 1000D firmware version 1.06 update.
4. Follow this link to download the Canon EOS Rebel XS / Canon EOS 1000D Instruction Manual.

I hope that helps.

Seems your Canon A80 camera got known problem of bad ccd imager IC that needs to be replaced.
Canon will replace ccd imager free of cost, click Canon CCD Imager Advisory for details.
Thanks.

RAM problem. Fix the RAM properly in the RAM slot.

If these are single pixels on the LCD screen, they are normal. From pg. 8 of the user's guide:

"The LCD monitor is manufactured using extremely high-precision technology so over 99.99% of the pixels are operational for effective use. However, there may be some tiny black points and/or bright points (white, red, blue or green in color) that constantly appear on the LCD monitor. These points are normal in the manufacturing process and do not affect the images in any way. "

This may also be helpful.

"images may trail across the LCD monitor in a cold location. This is not a malfunction. When turning on the camera in a cold location, the LCD monitor may become temporarily dark. "

It is known problem of CCD Imager Sensor in Canon A70 camera and this part will be replaced.
Canon will repair A70 Free of Cost for CCD Imager problem as per announced scheme.
Click Canon CCD Imager Support for details.