Owner's Manual

073-1246 Rev. C 9
© 2009, 2010 Apple Inc. All rights reserved.
Memory
Diagnostic LEDs
Important: The single-
and dual-processor boards
include a set of diagnostic
memory LEDs. After re-
installing or replacing
a DIMM, always use the
LEDs to verify the DIMM is
correctly seated.
To verify your DIMM
installation, do this:
1 Start up the
computer.
2 Remove the side
access panel.
3 Check the bank of
memory LEDs.
An illuminated, red
LED indicates its
associated DIMM may
be poorly seated or
failed.
4 If you see a red
LED, refer to “How
to Troubleshoot
Memory LEDs” on the
next page.
Note: Apple System
Proler does not report
unseated or failed
memory. You must use the
memory LEDs to locate
DIMM issues.
Single-Processor LEDs
Dual-Processor LEDs