FreeAgentTM | XTreme lights will not turn back on after they have been disabled and re-enabled in Seagate Manager.
This only occurs when the drive is connected via Firewire / 1394.
If the lights are disabled while the drive is asleep, and then you try to reactivate the lights, the lights will remain off.
Two Possible Solutions:
Toggle the lights on, then disconnect and reconnect the drive. The lights should return to normal.
Plug the drive in via USB and enable the lights. After that, you can safely remove the drive and reconnect via Firewire / 1394 and the lights will function normally.
For information on how to safely remove an external drive, see Document ID: 199611.
For information on how to toggle the lights on or off, see Document ID: 205731.