I just bought a new eSATA drive but it didn include a cable. What kind of cable do I need?
You want an “eSATA II” cable. The TiVo expects the longer connector found on eSATA II cables. The “eSATA I” cables feature a shorter connector which will not create a reliable connection with the Series3. Cables with a short connector are the #1 cause of problems with eSATA expansion on the Series3. See FAQ #26 for information on where you can order the right cable.