Apple Mac mini Late 2009 (Technician Guide) - Manual (Page 22)

Mac mini (Late 2009) Symptom Charts — Startup and Power 22 2009-11-03
Intermittent Shutdown
Quick Check
Symptoms Quick Check
Intermittent Shutdown
Powers off during startup. •
Powers off during desktop use. •
Computer restarts •
spontaneously.
Powers off when waking from
•
sleep.
Isolate OS by starting up from original Install 1.
media for the computer, the same make and
model computer in Target Disk Mode, or
compatible known-good OS on an external drive.
Both AirPort and Bluetooth services are available
when booted from the Install disk.
Reset SMC and PRAM to clear any stored,
2.
corrupted information.
Start up in Safe Mode by holding the shift key
3.
down during startup to load only required kernel
extensions and disable all startup and login
items. See KBase article
http://support.apple.com/kb/HT1564
Open System Preferences > Energy Saver > 4.
Schedule and make sure that a ‘Shut Down’ event
is not scheduled.
Make sure that power cord is securely attached to
5.
the back of the computer, and is not hindered by
a desk or other furniture.
Plug the computer directly into an AC outlet to
6.
test whether a surge protector, outlet strip, or UPS
is causing the issue.
Deep Dive
Check Result Action Code
Verify improper shutdown 1.
by opening the system.log
located in /var/log. Filter the
log for “shutdown cause”. Entries
of value “0” or a negative
value indicate an improper
shutdown. Did you find entries
of improper shutdown?
Yes Determine if user caused
improper shutdown. Use
known-good AC power cord
and AC outlet. Go to step 2.
No Revisit Quick Check examples
for possible software issues.
Check if user is running
other automating software
that may be shutting down
system. Verify issue and jump
to appropriate symptom
flow. No repair needed under
current symptom flow.