116 MACWORLD AUGUST 2019
HELPDESK MAC 911that your previously reliable external hard
disk drive or SSD starts ejecting itself,
trouble is obviously afoot.
The message “Disk Not Ejected
Properly” usually appears when you
unplug a cable or disconnect power to a
drive without making sure the disk has
unmounted from the Finder after
selecting it and choosing File → Eject
[Name] or
clicking the
Eject icon next
to its name in
the sidebar.
If happens other times, it’s never good.
Some readers have found this problem is
related to system software, and they go
through the standard set of hardware
parameter troubleshooting, such as
resetting NVRAM (go.macworld.com/nvrm)
and resetting SMC (go.macworld.com/
rsmc).
It’s worth trying, because it’s non-
destructive. If unexpected unmountings
continue, try to make a backup
immediately. This may reveal other
problems, but it’s important you have as
current a copy of what’s on that drive as
possible, as the hardware may be about to
die—or the drive may at least be hard to
access while you work through solutions.
Here are five other possibilities and
some accompanying ideas for
troubleshooting:
- 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 adapter 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
adapter is the culprit, because AC power
adapters 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