Led Activity - Juniper E Series Hardware Manual

ERX 7.0.x Hardware Guide
Figure 52: E3 and T3 Module LEDs

LED Activity

When the system boots, it runs a series of tests for each module installed in the
system, and the LEDs display various configurations. Refer to tables Table 12
and Table 13 to understand normal and abnormal LED activity.
NOTE: When you reboot the system after installing a new version of the software,
the line modules will appear to boot twice.
Table 12: Normal Activity of Functional Status LEDS During Booting
106
Understanding Status LEDs to Troubleshoot
OK FAIL
on
off
off off
Functional status LEDs
Interface status LEDs
ONLINE
off
off
Status Process
1. Module is in the
power-up restart
state; the FAIL LED
stays on briefly.
2. Module is
initializing, and
diagnostic tests are
running.