User Guide

iMac (27-inch, Late 2009) Symptom Charts — Startup and Power 33
2009-12-16
Wait 15 seconds after computer 3.
was powered down and
disconnect AirPort cable from
logic board. Verify if computer
starts up properly now.
Yes Go to AirPort Card Kernel
Panic symptom ow.
No Go to step 4.
Disconnect hard drive SATA 4.
cable and startup from Install
DVD in the optical drive, or
from an external bootable
volume. Verify if computer
starts up properly now.
Yes Go to Hard Drive Not
Recognized symptom ow.
No Go to step 5.
Reconnect hard drive, 5.
disconnect optical drive cable
and retest. Verify if computer
starts up properly now.
Yes Go to Optical Drive Not
Recognized symptom ow.
No Go to step 6.
Remove coin battery on back 6.
of logic board (you will need to
completely remove logic board
to do this), and leave out for
approximately 1 minute. Then
reinstall battery. This will reset
logic board. Verify if computer
starts up properly now.
Yes Issue resolved by logic board
reset. Measure DC voltage on
battery touching battery with
red probe, and grounding
with black probe. If voltage is
2.7v or less, replace battery.
For multimeter help, see
kBase #HT3250: Diagnostics:
Using a digital multimeter.
No Replace logic board. M02