On a canon Powershot S410, does both the batterypack and CF card have to be in the camera for the camera to power on?

No, you do not need a memory card in the camera for it to power on. You have another issue.

http://www.usa.canon.com/cusa/support/consumer/digital_cameras/powershot_a_series/powershot_a70#ServiceAndSupport

Issue: Memory card Error
Solution: Try a different memory card and/or Reformat memory card PowerShot A70


Formatting a CF Card You should always format a new CF card or one from which you wish to erase all images and other data.
Please note that formatting a CF card erases all data, including protected images and other file types. Please check the contents of the CF card before formatting it.

1. Turn the power on.
   
   
2. Press the <MENU> button and select [ (Set up)] using or .
   
   
   
   
3. Select (Format) using or and press the <SET> button.
   
   
   
   
4. Select [OK] using or and press the <SET> button.
   
   
   
   
   • To cancel formatting instead, select [Cancel] and press the <SET> button.
   • The capacity of the CF card displayed after formatting will be less than the rated capacity of the CF card. This is not a malfunction of the CF card or camera.
   
   
   
5. Press the <MENU> button.

• If the camera does not work properly, the inserted CF card may be malfunctioning. Reformatting the CF card may solve the problem.
• When a non-Canon brand CF card is malfunctioning, reformatting it may solve the problem.
• CF cards formatted in another camera, computer or peripheral device may not operate correctly. When that happens, reformat the CF card with this camera.

Take a look inside your camera's CF card slot. I suspect that you may have a bent pin in there. If so, don't fret. Although professional repair would be more costly than the value of the camera, there is a very good chance that you can repair this yourself. Please see this link.

You can get the back cover from ebay...

http://stores.ebay.ie/Nanites-Camera-Services_Spare-Parts_W0QQfsubZ1500748

let me know if you need further assistance. Kevin

Did you format the card in the camera? Generally you have to do that before you can use it. Try that and see if it doesn't fix your problem.

Rob

The Canon G1 was my first digital camera, years ago. When this camera was sold it came with a 16 Mb CF card. The manual refers to CF card sizes from 8 Mb up to 128 Mb and the number of photos you can take with each size card. However, I bought my camera together with a 1GB "micro drive" (tiny hard drive in a CF card format) and although it wasn't "supported" by Canon, it worked fine. I also used a regular 1GB CF card in it (after I lost the microdrive card). If you want to use a card larger than 1GB with this camera, test/borrow a card to make sure it works before you buy one. Camera stores always have a variety of cards (used to demonstrate the cameras they are selling) that you can put in your camera and test before you decide which card to buy.

If on the camera, try a card reader. pop it out and put it in the reader and hook it to the PC.

If corrupted when viewing on PC. the card may need reformatting.

With CF card it is VARY important not to remove it while it is writing. best thing when taking it out of the camera is to turn the camera off and wait until it is fully powered down before removing the card.

Check your memory card to see if its locked!

Limited only by the size of the memory module that is currently available on the market. 512 to 64gb but over 2GB your camera has to support FAT32 format and I'm not sure if it does. It can connect to a PC running XP so one might assume it handles FAT32 files. Here's some more info: http://en.wikipedia.org/wiki/Compact_Flash http://web.canon.jp/imaging/PSA60/index-e.html

Try to use the CF in another camera to find out whether your problem is the CF or the camera. Good luck!