- IBM switch Users and Maintenance Guide

Table 17. Symptom-to-FRU index (continued)
Problem
indicator Component Possible cause Possible solutions
One or more
green LEDs off
(continued)
Expansion loop Drives are
improperly
installed or not
installed
Ensure that the drives are
properly installed.
RAID controller
has no power or
has failed
Ensure that the unit is powered
on. Replace the RAID controller.
Impending drive
failure
A bad drive or drives can issue
LIPs that cause the drive
expansion loop to go down
momentarily. Use the RLS
function in the DS4000 Storage
Manager client to determine
which drives are bad. Replace
the bad drives.
Externally
attached
expansion port
device has failed
Replace the expansion unit SFP
or fibre-channel cable.
Intermittent or
sporadic power
loss to the storage
server
Some or all CRUs Defective ac
power source or
partially
plugged-in power
cord
Check the ac power source;
verify that the ac circuit that the
storage server connects to is not
being overloaded. Reseat all
installed power cables and power
supplies. If applicable, check the
power components. Replace
defective power cords.
Power supply
has failed
Check for a Fault LED on the
power supply, and replace the
failed CRU.
Midplane has
failed
Have the midplane replaced
(service technician only).
Unable to access
drives
Drives and
expansion loop
Fibre-channel
cabling has
failed.
Ensure that the fibre-channel
cables are undamaged and
properly connected.
RAID controller
has failed
Replace the RAID controller.
SFP has failed Ensure SFP is seated properly;
replace SFP.
Random errors Subsystem Midplane has
failed
Have the midplane replaced
(service technician only).
114 IBM TotalStorage DS4100 Storage Server: Installation, User’s, and Maintenance Guide