IBM totalstorage 326 User Reference page 133

Table 22. Storage unit troubleshooting table (continued)
Problem Indicator Component
Intermittent or Some or all CRUs Defective AC
sporadic power loss to
the expansion unit
Unable to access Drives and FC
drives loop
Random errors Subsystem
Note: If you cannot find the problem in the troubleshooting table, test the entire
system. See your storage unit documentation for more detailed information
on testing and diagnostic tools.
Possible Cause Possible Solutions
1. Check the AC power
power source or
source.
partially plugged
2. Reseat all installed
in power cord
power cables and power
supplies.
3. If applicable, check the
power components
(power units, UPS, and
so on).
4. Replace defective power
cords.
Power supply Check for a Fault LED on
failure the power supply and
replace the failed CRU.
Midplane failure Have the midplane replaced
(service technician only).
Incorrect ID
1. Ensure that the FC
settings
optical cables are
undamaged and
properly connected.
2. Check the drive ID
settings.
Note: Change switch
position only when the
expansion unit is powered
off.
ESM board failure Have one or both ESM
boards replaced.
Midplane failure Have the midplane replaced
(service technician only).
Chapter 8. Troubleshooting
121