Troubleshooting guide

2. Troubleshooting Switch Failures
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Table 2-5: Isolating the cause of external redundant power unit failures
Table 2-6: Isolating the cause of external redundant power unit hardware faults
Table 2-7: Isolating the cause of power supply module failures
2.2.3 Replacing the switch and optional modules
The procedure to replace the switch and optional modules is described in the Hardware Instruction
Manual. Follow the instructions in the manual.
No. Problem Action
1 The POWER LED of the EPU is lit in green. Identify the power supply module that is not operating properly
by checking the LEDs of the power supply modules mounted on
the EPU. When power supply modules are operating properly,
the following conditions apply:
• For EPU-A
DC-OK: Lit in green, DC-ALM: Off
• For EPU-B
DC-OK: Lit in green, DC-FAIL: Off, AC-OK: Lit in green
Perform the steps shown in Table 2-7: Isolating the cause of
power supply module failures on the power supply module that
is not operating properly.
2 The POWER LED of the EPU is off. Perform the steps shown in Table 2-6: Isolating the cause of
external redundant power unit hardware faults.
No. Problem Action
1 The power switch of the EPU is off. Turn the power switch on.
2 The power cable of the EPU is not correctly
connected to the switch.
1. Turn the power switch off.
2. Connect the power cable correctly.
3. Turn the power switch on.
3 The input power supply to the EPU is outside
the following range:
(AC power supply: 90 to 132 V)
This is a power facility failure (not a switch fault). Ask the
system administrator to take action.
4 Failure other than the above Replace the EPU.
No. Problem Action
1 The power switch of the power supply module is
off.
Set the power switch of the power supply module to ON.
2 The power cable of the power supply module is
not correctly connected to the switch.
1. Set the power switch of the power supply module to OFF.
2. Connect the power cable correctly.
3. Set the power switch of the power supply module to ON.
3 The power supply module is not properly
installed on the EPU.
1. Turn the power switch off.
2. Install the power supply module correctly.
3. Turn the power switch on.
4 Failure other than the above Replace the power supply module.