No pix on memory card...E18 msg on camera..

What type and size memory card? The A620 works with MMC and SD cards, 2GB or smaller. It will not work with higher-capacity SDHC cards.

Some cameras cannot handle over 2GB memory cards. If it works fine with 2GB card - stick to that. If some other A620 you know operates with 4GB card, take yours to repairs.

Your camera has a board with the SD card slot board and electronics to record and retrieve images. This board can be replaced and should cost about $100 to repair.

The camera sensor is bad. It can be replaced if you still have warranty. If its out of warranty, get a new camera - the cost to repair = cost of new camera.

there should be a little swith on the side of the card. switch to the opposite and then try

the a 620 only goes up to 2 gb no higher

If the camera displays "Communication Error," when trying to download images the main cause for this error is that there are more than 1000 images stored on the memory card. It is recommended if there are more than 1000 images on the memory card, that you use a card reader to acquire the images, or to delete images off of the memory so that there are less than 1000 images to download from the memory card.
If this is not the case, there are not 1000 or more images on the memory card, try reconnecting the camera to abnother port on the computer, try another cable or another computer. This error can also display when connecting to a direct print printer. Please check with the printer manufacturer for more information on this error.

First off what is the size of the mem card? Second did you make sure that you formatted the mem card with the camera before you tried to use it? What I would recommed is transfer your files to your computer FIRST. Then format the internal memory of the camera once you have transfered them over. Insert your memory card and then format the mem card. Turn the camera off and take your mem card out. Try taking a video. Turn off camera. Put mem card back in and see if you can transfer that video now and it should work.

hi , try to connect computer via usb scan with anti virus.

SkiPowder, the E18 error is fairly common. Usually it's sand or grit interfering with the lens extension mechanism. Or the camera's been dropped with the lens extended. Or the camera has been powered on, but the lens had been blocked preventing its extension.
Here's some things that you can do to try to correct it. Have already fixed several cameras with this problem by using these methods:
http://www.e18error.com/repair.html
Guest has a different problem. Guest's problem 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 cameras 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