20 Most Recent Canon PowerShot A710 IS Digital Camera Questions & Answers

The reason is that the images were not created on the camera in question. Each camera model saves pictures on a card in a proprietary naming protocol, and if your images do not adhere to this, they cannot be recognised by the camera

If the SD card is housed in the same compartment, it is not loaded properly. The card holder is fitted with a spring mechanism to eject, therefore it will exert an outward pressure against the door. This will displace the locking/ unlocking mechanism of the door and will be impossible to open in the normal way. Tips for opening, refer to my previous answers to similar questions.

Here are some simple things to try first for a camera that won't take a picture when the shutter button is pressed, or with an inoperative flash. They won't work for every case, but they're worth a try:
http://camerarepair.blogspot.com/2008/05/simple-fixes-for-cameras-that-wont-take.html

My experience in the past when this occurs is that the power board has been fried. That being said the repair has always been a complete replacement of the power board. It's most likely cheaper to replace the camera

CCD = charge coupled device. The sensor that "sees" the image.

Try NOT connecting your camera to your computer. The best way to download pictures from your camera to your computer involves removing the memory card from the camera and plugging it into a card reader (either built-in to the computer or connected via USB or FireWire). This is likely to be faster than connecting the camera to the computer, and won't run down your camera's batteries. Once the card is plugged in, it will appear to your computer as a removable drive. You can use the operating system's drag&drop facility to copy pictures from the card to the computer's hard drive, the same way you copy any other files. Or you can use any photo management program such as Picasa ( http://picasa.google.com ).