Intel-based Mac may become unresponsive in target disk mode
Issue or symptom
Some Intel-based Macs can become unresponsive while being used in FireWire target disk mode for long periods of time. The FireWire icon will stop moving, and the disk cannot be accessed from another Macintosh computer over FireWire.
This behavior can be corrected with a firmware update to the computer that becomes unresponsive while in Target Disk Mode. Startup that computer into Mac OS X, then follow the instructions in this article.