the camera is switched on but the screen is completely blank. What should i do???

First thing I would do is reset the camera. This is a fairly easy procedure which involves either going into your setup menu and choosing "reset," holding down the menu key for 5 seconds, or, removing the batteries for a few minutes. It may be that the firmware loading got corrupted and the camera just needs to be "rebooted," which is something that turning it on/off won't accomplish. But after which, you should have the camera reset to factory default settings.

Another tip is to go to Canon's website and look for firmware updates. Download and install them.

Also, you may want to contact Canon to see if there's a service advisory for this issue. Although your model is not included in it, it sounds alot like what one of a host of cameras have suffered from a faulty CCD chip. Check out this from Canon regarding it.

Affected products:

- Camcorders: ZR60, ZR65 MC, ZR70 MC, ZR80, ZR85, ZR90, ELURA 40 MC, ELURA 50
- Digital Cameras A60, A70, A75, A300, A310, S230, SD100, SD110, A40(*), A80(*), A85(*), A95(*), S1 IS(*), S60(*), S200(*), S330(*), S400(*), S410(*), S500(*)

Malfunction:
It has been confirmed that the connecting parts of the internal wiring of the CCD used in affected products may become disconnected, especially if the affected products are stored or used in high-temperature and high-humidity environments. If this occurs, the signal is not output from the CCD normally in Shooting Mode, which may cause a distorted image or the absence of an image. This malfunction can be confirmed on the LCD monitor screen during shooting. The same malfunction also appears on the recorded image.

Canon's Response:
Effective immediately, and regardless of warranty status, Canon will repair, free of charge, the products listed above exhibiting the above-mentioned malfunction if Canon determines that the malfunction is caused by the CCD image sensor. Canon will also cover the cost of shipping and handling in connection with this repair.

So the good news is that Canon will fix it for FREE:

U.S. residents are kindly directed to contact the Canon Customer Support Center for further assistance at 1-800-828-4040. Support hours are Monday thru Friday - 8:00 AM to 12:00 midnight; and Saturday 10:00 AM to 8:00 PM (all times EST). Alternatively, if electronic support is preferred, please send your email to carecenter@cits.canon.com

I have the Black Screen of death. Tech Support does not care. Pay to fix it or throw it in the junk and avoid the PowerShot. Beware.

Well, from their perspective, the warranty is expired. However, if you bought this camera with a credit card, all may not be lost. Contact your credit card company and see if there is an extended warranty benefit for using the card for the purchase. If so, you may still be able to have it fixed on their dime, not yours.

I have the same problem, black screen! I just called the company and gave me two options: send back for repairs (won't know the cost until they see it) or exchange for a refurbished S3 which it will cost me $185. Anyone has any opinion on what will be better. Is the refurbished S3 worth the money?

GO WITH THE S3. Or better yet, take that $185 and invest toward either the S5 or another model like perhaps the Olympus SP560UZ.