Cover open, camera does not turn on.

Close the [Memory Card / Battery Cover] securely, and then turn the power on.

Clean the battery terminals with a dry cotton swab that has a fine and soft tip, and then re-insert the batteries.

If your camera uses four AA-size alkaline batteries supplied with the camera, follow the procedure below. In addition to Alkaline batteries you may use optional nickel metal hydride (NiMH) batteries.

1. Be sure that the camera power is off.

2. Slide the battery cover lock in the direction of the arrow, and push the battery cover slightly forward. Then open the cover.
3. Insert the batteries as shown.
4. Close the battery cover.
* For the PowerShot S2 IS, PowerShot S3 IS, and PowerShot S5 IS the batteries are inserted in a slightly different order, please refer to the decal inside the battery door for the correct order.
Installing batteries in cameras with 2 batteries. If your camera uses two AA-size alkaline batteries supplied with the camera, follow the procedure below. In addition to Alkaline batteries you may use optional nickel metal hydride (NiMH) batteries. Please see the various examples to find which type matches your camera.
Example 1:

1. Be sure that the camera power is off.
2. Slide the battery/memory card cover lock in the direction of the arrow (), and press down while opening the cover ().
   
   
   
3. Insert the batteries as shown and close the battery / memory card cover.
   
   

1. Be sure that the camera power is off.
2. Slide the battery cover lock in the direction of the arrow, and open the cover.
   
   
3. Insert the batteries as shown.
   
   
   
4. Close the battery cover.