The problem appears to be that the power harness used in the Digi 002 is defective. (References: here and here). DigiDesigns will replace the harness for free, but the user has to install it themselves. This isn’t particularly tricky, since they send you complete and easy-to-follow instructions. The tricky part is working out what’s wrong, since there’s no sensible error messages from their software and no clear indication of a hardware error. Even worse, the hardware error is often intermittent, seeming to go away for long periods before returning.

Hardware Symptoms:

• When the IEEE1394 interface cable is connected, the green link light (on the back of the case, right between the IEEE1394 ports) briefly turns on then immediately turns off again.
• The Mute light on the front of the case remains lit. No other lights are on. The device is unresponsive.
• When attempting to establish a connection, the link light blinks on, a click is heard, then the light immediately turns off again. This repeats several times.

Software Symptoms:

• When starting ProTools LE, the following error message is seen: “Unable to locate Digidesign hardware. Make sure your hardware is connected and turned on. Click “Ok” when the hardware is ready.”

Getting a Replacement Part:

The replacement part is user-serviceable. Call the technical support line (free if you’re under warranty, $3/minute up to $75 or so if you’re not) and describe the problem to them. They should e-mail you a waiver of liability for the user-installed parts. Once you read and agree to that, they’ll mail you a replacement part and instructions for installing it. The part should arrive inside of a week.

Hopefully, this post will be useful to anyone else who runs into this problem.