5-4
Troubleshooting
Diagnosing with the LEDs
Troubleshooting
Diagnosing with the LEDs
Table 5-1 shows LED patterns on the switch and the switch modules that 
indicate problem conditions.
1. Check in the table for the LED pattern you see on your switch.
2. Refer to the corresponding diagnostic tip on the next few pages.
Table 5-1. LED Error Indicators
LED Pattern Indicating Problems
Diag 
Tips
Power Fault PS Tmp Test
Fan 
Status
Port LED
(in Link view mode)
Off with 
power cord 
plugged in
*PS LED off 
or blinking 
orange
*** *
➊
On Prolonged On * * Prolonged 
On
**
➋
On Blinking
†
**Blinking
†
**
➌
On Blinking
†
* * Off Blinking
†
*
➍
On Blinking
†
**Blinking
†
* Blinking
†
➎
On Off * * Off * Off with cable 
connected
➏
On Off * * Off * On, but the port is 
not 
communicating
➐
On Blinking Blinking * Off * *
➑
On Blinking * Blinking Off * *
➒
* This LED is not important for the diagnosis.
†
The blinking behavior is an on/off cycle once every 1.6 seconds, approximately.