IBM DS4800 Installation, User And Maintenance Manual page 160

controller (controller A); power to the left power supply and fan unit is routed
through the bottom controller (controller B).
If a circuit breaker has tripped, the condition might appear as if a power supply and
fan unit has failed. The power supply is no longer providing power to the storage
subsystem. A tripped circuit breaker is indicated when all of the following conditions
are present:
v The Overall DS4800 Configuration Needs Attention LED on the storage
v The controller Needs Attention LEDs are not turned on.
v The power supply and fan unit Needs Attention LEDs are not turned on.
v The Service Action Allowed LED is turned on for the power supply and fan unit
v The DS4000 Storage Manager client shows the power supply and fan unit has
Use the following procedure to reset the circuit breaker.
Tools and Equipment
v Antistatic protection
v Nonconducting stylus
Electrostatic discharge can damage sensitive components – Touching the
storage subsystem or its components without using a proper ground might damage
the equipment. To avoid damage, use proper antistatic protection while handling
any components.
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IBM System Storage DS4800 Storage Subsystem: Installation, User's, and Maintenance Guide
subsystem front bezel is turned on.
connected to the controller with the open circuit breaker.
failed.
1. If the alarm is sounding, turn off the alarm.
2. Check to ensure that the external power cables are completely plugged into
the controllers and into the power source.
3. Put on antistatic protection.
4. Remove the front bezel by grasping the sides and pulling the cover toward
you.
5. Check the Needs Attention LED on each power supply and fan unit. (Figure 79
on page 133 shows the left power supply and fan unit Service Action Allowed
LED is the top, or first, LED, and the Needs Attention LED is the second LED.
On the right power supply and fan unit the Service Action Allowed LED is the
bottom, or fifth LED, and the Needs Attention LED is the next, or fourth, LED.)