IBM H Series Installation And Service Manual page 64

Step 1520-12
Check that the power outlet is properly wired and is providing the correct voltage.
Did you find a problem?
NO Go to "Step 1540-1" on page 2-38.
YES Correct the problem. Go to "MAP 410: Repair Checkout" in the
Diagnostic Information for Multiple Bus Systems.
Step 1520-13
Since the H Series Enterprise Server can have redundant power supplies, it is not
necessary to power down the system in order to replace a power supply. The power
supplies are symmetrical so replacement starts with the left-hand unit (Power Supply
1). The exception to this rule is if the green LED on the back of one of the power
supplies is either blinking or not lit. In this case start with that power supply. See
"Power Supplies and Power Supply Fan Assemblies" on page 7-21 for instructions
on replacing a power supply. Before removing a power supply be sure the "other"
power supply is operational by observing the green LED, which should be lit. Also
be aware that the power supply exchange process must be completed within five
minutes, including moving the fan assembly from the removed supply to the replace-
ment power supply. After five minutes, the Service Processor shuts the system
down to avoid overheating devices in the media and DASD bays.
Replace the following FRUs in order:
1. Power Supply 1
2. Power Supply 2
Perform Error log Analysis.
Do you receive an SRN indicating a Voltage Sensor out of range?
NO The last FRU exchanged is defective. Go to "MAP 410: Repair Checkout"
in the Diagnostic Information for Multiple Bus Systems.
YES Reinstall the original FRU.
Repeat the FRU replacement steps until a defective FRU is identified or
all the FRUs have been exchanged.
2-30
RS/6000 Enterprise Server Model H Series Installation and Service Guide