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.

Solution

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.