Apple Mac Pro (Memory DIMMs Replacement) - Manual (Page 9)

073-1246 Rev. B 9 © 2009 Apple Inc. All rights reserved.
Memory
Diagnostic LEDs
Important: The quad-
core and 8-core 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:
Start up the
1
computer.
Remove the side
2
access panel.
Check the bank of
3
memory LEDs.
An illuminated, red
LED indicates its
associated DIMM may
be poorly seated or
failed.
If you see a red
4
LED, refer to “ How
to Troubleshoot
Memory LEDs
” on the
next page.
Note: Apple System
Profiler does not report
unseated or failed
memory. You must use the
memory LEDs to locate
DIMM issues.
Quad-Core LEDs
8-Core LEDs