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Cisco ME 4924-10GE Ethernet Switch Hardware Installation Guide
OL-10071-01
Chapter 4 Troubleshooting
Troubleshooting the Hardware Components
LED Readings
LEDs indicate all system states in the startup sequence. By checking the LEDs, you can determine when
and where the system failed in the startup sequence. To check the LEDs, follow these steps:
Step 1 Compare the LED states to Table 4-2:
Step 2 Verify that the LEDs on the front panel are lit:
• The STATUS LED flashes amber during diagnostic boot tests. It is green when the switch is
operational (online). If the system software is unable to start up, this LED stays orange.
• The port LEDs (1-48) are green when the module is operational (online). If no signal is detected,
the LINK LED is off. The port LED remains amber if the port is disabled. The port LED flashes
amber if the port tested faulty at startup.
Step 3 If a STATUS LED is red, contact a customer service representative for instructions.
Step 4 If the boot information and system banner are not displayed, verify that the terminal is set correctly and
that it is connected properly to the console port.
Table 4-2 Power Supply LED Meanings
LED and Color Meaning
INPUT OK (AC)
Green
Red
Off
This LED should turn green immediately when power is
applied to the supply and the power switch is set to ON.
AC input voltage is greater than 82 +/-3V.
In a dual power supply configuration (alternate unit
powered) the AC input is less than 73 +/-3V, or the power
supply is turned off.
AC input voltage is less than 73 +/-3V, or the power supply
is turned off.
INPUT OK (DC)
Green
Red
Off
This LED should turn green immediately when power is
applied to the supply.
DC input voltage is greater than -38.25 +/-2.25V.
In a dual power supply configuration (alternate unit
powered) the DC input is less than 33 +/-3V, or the power
supply is turned off.
In a single supply configuration, the LED shall be off to
signal that DC input is less than 33 +/-3V, or the power
supply is turned off.
OUTPUT OK
Green
Red
DC output voltages are within the normal operating range.
Output voltage between the minimum and maximum limits
will not create an output fail alarm. Output voltages below
the minimum or above the maximum will create an output
fail alarm and cause the LED to illuminate red.
