Led Activity During Booting - Juniper ERX-1410 Installation And User Manual

Understanding Status LEDs 8-7
ERX Edge Routers
Figure 8-2 FE2 module LEDs
Figure 8-3 E3 and T3 module LEDs

LED Activity During Booting

When the system boots, it runs diagnostic tests, and the module status
LEDs display various configurations. Observe the scenario presented in
Table 8-3 to verify that the system has booted properly.
Note: When you reboot the system after installing a new version of the software,
the line modules will appear to boot twice.