URGENT HELP NEEDED (editing a film) G4 0S 10.4

Some external drives don't power themselves down because their power is taken from a mains power cable, rather from USB or Firewire - so it is totally separate. Some drives are designed to power off when they do not have a USB or Firewire signal, some are not. So if you want it to power down, unplug it. As for it no longer appearing, you may want to try plugging it in to another computer to see if it appears there. If it appears on a different computer, then it's likely to be something wrong with the OS on your system - it could be that you've had it connected in the daisy chain before and now you have it singluarly connected the drivers are not being loaded properly because it would've been using the other disk's drivers as it would've gone through the daisy chain - and now it can't communicate. If it does not work in other computers, the drive is bricked and will need to be returned to the manufacturer. I'm not familiar with Macs either, however if it works with other computers, but you're at a dead end with your computer, a surefire way to fix it is to reinstall your OS.

These units have problems with the hibernate/sleep functions of windows. It should power down when the PC actually is fully shut down, but not when it goes into sleep mode. Well, for starters you probably want to go into the driver settings and turn off the long strip of light. It serves no real purpose but has been reported to cause heat issues. I'm slightly worried that these heat issues may be what's causing your problem. Once you've done that, disconnect the power and USB from the drive. Let it sit for a good 10 minutes, to make sure it's fully cooled down, then plug the power back in, and then the USB cable. If that doesn't restore it, you'll have to remove it from device manager. Disconnect the USB again. Then right click on your my computer icon (either on your desktop or your start menu) and choose properties. That brings up a System Properties window. Click on the Hardware tab, and then on Device Manager. In Device Manager, look for this drive. You may have to hit a couple + signs to expand some things before you find it. Right click on it, and choose uninstall. Once that's done, reboot for good measure (you PROBABLY don't need to reboot, but it never hurts), and then plug the USB back in. It should detect and reinstall the drive. If you do that, you'll want to go back into the driver settings and disable the light again.