Led Readings - Cisco 4948 - Catalyst Switch Installation Manual

Appendix C Troubleshooting the Installation

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:
Compare the LED states to those in
Step 1
Table C-1
LED and Color
INPUT OK (AC)
INPUT OK (DC)
OUTPUT OK
OL-21561-02
Table
Power Supply LED Meanings
Meaning
This LED should turn green immediately when power is
applied to the supply and the power switch is set to ON.
Green—AC input voltage is greater than 82 ±3 V.
•
Red—In a dual power supply configuration (alternate
•
unit powered) the AC input is less than 73 ±3 V, or the
power supply is turned off.
Off—AC input voltage is less than 73 ±3 V, or the
•
power supply is turned off.
This LED should turn green immediately when power is
applied to the supply.
• Green—DC input voltage is greater than -38.25
±2.25 V.
Red—In a dual power supply configuration (alternate
•
unit powered) the DC input is less than 33 ±3 V, or the
power supply is turned off.
Off—In a single supply configuration, the LED shall
•
be off to signal that DC input is less than 33 ±3 V, or
the power supply is turned off.
Green—DC output voltages are within the normal
•
operating range.
Red—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.
Catalyst 4948E and Catalyst 4948E-F Switch Installation Guide
C-1.
Identifying Startup Problems
C-3