122 Macworld • August 2019HELP DESK
- A bad cable
Even if you haven’t touched the cable since you
attached an external drive years ago to a desktop
computer, cables can fail. This is true even if it’s
the one included with the drive or you purchased
one from a company with strong positive product
reviews. Cable failure is more likely for drives that
are routinely connected and disconnected to a
computer. Swap another identical cable, as it’s
the cheapest way to isolate the problem. - A faulty power connection
Check that the adaptor is plugged in to the drive
firmly and that the AC power plug isn’t jiggling in the
outlet or surge protector. If the drive has a power
light separate from an activity LED, observe it and
see if it’s flickering or otherwise inconstant.
Even with a power light, it can be tough to
monitor and hard to test if a power adaptor is the
culprit, because AC power adaptors are rarely the
same among different companies (or even models
of drive from the same company). You may need
to call the company or use online tech support
to get additional troubleshooting. The company
may be able to send you free or for a small fee a
replacement adaptor if it thinks that’s the problem. - The drive’s case is going bad
This is another hard thing to diagnose separate
from the drive. A drive has its own operating
system, circuit boards, and chips, but a case also
has components, firmware, and a power supply