Do I have to turn the power off to remove my CompactFlash card?
In most cases, no. As long as your device isn’t currently accessing the card, you can usually “hot swap” one card for another without turning off the power, much the same way you would with a floppy disk on your computer. To be on the safe side, double-check the owner’s manual for your device for specific instructions for removing and installing your CompactFlash cards. If you experience problems hot swapping the card, try turning off power before inserting the card to see if the problem is corrected.