Q&A: FireWire draining power

Q I backed up my now-deceased Mac to a FireLite Smartdisk (FireWire). Having bought a MacBook Air, I obtained a FireWire-USB adaptor, but when I try to connect the disk using that, the Mac complains that it is drawing too much power from the USB port. How can I access this external hard disk now?

A You may encounter this when trying to connect some FireWire devices to USB ports. It occurs because a FireWire port can deliver considerably greater power – up to 45 W on a good day – than a standard USB port which may offer as little as 2.5 W, and your external disk is demanding too much.

If the drive can have an external mains adaptor to power it, try using that, powering the drive up before connecting it to the USB port. You may have better luck on a desktop Mac, which normally offers more power through its USB ports than the MacBook Air.

However FireWire devices can still try to draw more power than even those on a Mac Pro can provide. If all else fails, locate someone with a Mac that has a genuine FireWire port, and use that to transfer the contents of the disk to a powered external drive which will work with your MacBook Air.

Updated from the original, which was first published in MacUser volume 28 issue 06, 2012.