IBM DCS9550 1S1 - Manual (Page 59)

Troubleshooting and Problem Solving
44 IBM System Storage DCS9550 1S1 Storage Expansion Unit Installation, Service, and User Guide
4.5.4 Thermal Alarm
4.5.5 Thermal Shutdown
Important For thermal warnings please refer to the SES specification.
An Enclosure will shut down when a critical temperature threshold is exceeded in order to
prevent permanent damage to the disk drives.
4.6 Drive Carrier Module Faults
Disk drive status is monitored by a Green LED and an Amber LED mounted on the front of
each Drive Carrier Module, providing the following indications:
Drive activity - LED may be off for a length of time during power up.
Symptom Cause Action
1 Ops Panel FAULT
LED AMBER.
2 An AMBER LED on
one or more Power
Supply/Cooling
Modules.
3 Audible Alarm
Sounding.
4 Air temperature
exiting PSU above
55°C.
If the internal
temperature measured in
the airflow through the
enclosure exceeds a pre-
set threshold a thermal
alarm will sound. 1 Check local ambient environment
temperature is below the upper 40°C
specification.
2 Check the installation for any airflow
restrictions at either the front or rear
of the enclosure. A minimum gap of
25mm at the front and 50mm at the
rear is recommended.
3 Check for restrictions due to dust
build-up, clean as appropriate.
4 Check for excessive re-circulation of
heated air from rear to the front, use
in a fully enclosed rack installation is
not recommended.
5 If possible shutdown the enclosure
and investigate the problem before
continuing.
Table 4–4 LED Functions
State Green Amber
No drive fitted Off Off
Drive Power ON On Off
Drive Activity On/Blink off Off
Drive Fault On On