1. Make sure your device control cable is properly connected.
2. Make sure the appropriate protocol for your device is selected in the device control preset you're using (see Viewing settings for a preset). If you're using FireWire, try changing the protocol to Apple FireWire Basic.
3. If your deck has a Local/Remote switch, make sure it's set to Remote.
4. Some DV camcorders and decks require special scripts, which are installed in the Final Cut Pro Plugins folder. These scripts are also on your Final Cut Pro CD. Check the Final Cut Pro Web site to find out which script, if any, should be installed.