Recovering From An Overheated Power Supply - IBM DS3500 Installation, User's, And Maintenance Manual

v A storage subsystem in an optimal state recovers automatically from an unexpected shutdown and
unattended simultaneous restoration of power to system components. After power is restored,
contact your IBM technical-support representative if any of the following conditions occur:
– The storage subsystem logical drives and subsystems are not displayed in the Storage Manager
graphical user interface.
– The storage subsystem logical drives and subsystems do not come online.
– The storage subsystem logical drives and subsystems seem to be degraded.
4. Turn on the power to each device, according to the startup sequence.
5. If there are enclosures with dc power supplies in your storage subsystem, turn on the -48V disconnect
devices before turning on the power-supply switches.
6. Turn on both of the power-supply switches on the DS3500. The green LEDs on the front and the rear
of the DS3500 should remain lit. If other amber LEDs are lit, see Chapter 6, "Solving problems," on
page 6-1.

Recovering from an overheated power supply

Each storage subsystem contains two power supplies. Each power supply contains a built-in temperature
sensor to prevent the power supply from overheating. Under normal operating conditions, with an
ambient air temperature range of 10°C to 40°C (50°F to 104°F), the fans in the power supplies maintain a
suitable operating temperature inside the module.
If the internal temperature reaches 65°C (149°F), the power supply shuts down automatically. If both
power supplies shut down because of overheating, the storage subsystem has no power, and all LEDs are
off.
The following factors can cause the power supplies to overheat:
v An unusually high room temperature
v Fan failures in the power supplies
v Defective circuitry in a power supply
v Blocked air vents
v Failures in other devices in the configuration or rack
If a fan failure causes overheating, the system-error LED and overtemperature LEDs on the storage
subsystem are lit. The fault LED on the power supply might also be lit. "Checking the LEDs" on page 4-7
shows the location of the LEDs on the DS3500.
If the storage subsystem temperature exceeds 45°C (113°F), the storage management software displays a
Needs Attention icon in the Subsystem Management window. If the air temperature inside the rack
reaches 65°C (149°F), the power supplies automatically shut down. If event monitoring is enabled and
event notification is configured, the software issues two critical-problem notifications.
v If one power supply shuts down, the storage management software displays a Needs Attention status
in the Subsystem Management window.
v If both power supplies shut down, the storage subsystem shuts down, and the storage management
software displays a Not Responding status in the Array Management window.
Attention: To prevent damage to the storage subsystem components when the power supplies
automatically shut down, immediately remove all rack panels to help reduce the rack air temperature.
To resume normal operation after a power-supply shutdown, complete the following steps:
1. Did you use the procedure "Troubleshooting the storage subsystem" on page 4-6 to identify an
overheating problem?
v Yes: Go to step 2 on page 4-19.
4-18
System Storage DS3500 and EXP3500: Installation, User's, and Maintenance Guide