Re: Disappearing ang reappearing 2011 Mac Mini components
- From: dempson@xxxxxxxxxxxxx (David Empson)
- Date: Sun, 15 Jan 2012 14:44:11 +1300
Chance Furlong <T-Bone@xxxxxxxxxxxxxxx> wrote:
I was futzing with my 2011 Mac Mini several days ago, and the SD card
reader and ethernet cards disappeared and yesterday they reappeared and
are working normally.
At what point did they disappear? Were they missing from startup, or
disappear when waking from sleep, or were they working normally then
suddenly weren't there any more?
Have any of you experienced this and why would they disappear and
reappear?
Not those components, but I did have the Bluetooth capability disappear
and reappear a couple of times on my mid 2007 Mac Mini. The Bluetooth
controller is a USB peripheral in that model.
Bluetooth capability simply vanished while the computer was active (e.g.
the Bluetooth menu extra said something like "No bluetooth hardware
present", and the System Preferences Bluetooth panel vanished). All
other features of the computer continued to operate fine. System
Profiler showed no Bluetooth capability and the USB device tree had no
evidence that the Bluetooth controller was present. A restart fixed it
each time. I speculated it might have been a heat issue, since it only
happened during summer.
For your Mac Mini, the simultanous disappearance of two peripherals
suggests one of the following:
(a) Software or driver issue, possibly caused by a hard drive problem
(e.g. failed to load some drivers at startup). There may be clues in
/var/log/system.log around the time those components disappeared.
(b) Hardware problem causing intermittent failure in a single component
which is involved in connecting to both the SD card reader and Ethernet
controller.
(c) Simultaneous intermittent hardware failures in the SD card reader
and the Ethernet controller. This seems highly unlikely.
(d) A hardware issue involving the power supply, which affected those
peripherals but wasn't noticed by others. This seems highly unlikely.
The second case can investigated further by looking into exactly how the
SD card reader is connected on your Mac Mini. On my mid 2010 MacBook Pro
it is a USB peripheral (visible under the USB category in System
Profiler as "Internal Memory Card Reader"). Later models may have
switched to a direct PCI connection for extra speed.
The Ethernet controller will be connected via PCI. If the SD card reader
is also connected via PCI, then a problem with a single PCI bridge
involved with both the SD card reader and Ethernet controller might
explain the fault.
If the SD card reader is connected via USB and the Ethernet controller
via PCI, it seems highly unlikely that they would both be affected by a
single point of failure, without other USB peripherals being similarly
affected.
The command line "ioreg" tool provides more details than System Profiler
as to how the various internal peripherals are logically arranged. If
you have TextWrangler with its command line tools, a useful way to
browse through the output for ioreg is with this command:
ioreg -w 0 | edit
--
David Empson
dempson@xxxxxxxxxxxxx
.
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- Disappearing ang reappearing 2011 Mac Mini components
- From: Chance Furlong
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