Juniper Networks E-Series - Manual (Page 129)

Understanding Status LEDs to Troubleshoot
E-Series Routers
10-7
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 10-3 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.
If the system detects an error during booting, the FAIL LED turns on.
Some failure conditions may cause the board not to boot. In this case, the
LEDs may all be off. The system should then reset the board.
If the operational software detects an error, the FAIL LED turns on.
Some errors may cause a board reset. Crash information can be displayed
from the console and is printed to the screen on the next reboot.
Abnormal LED Activity
See Table 10-4 to diagnose and correct problems.
Table 10-3 Normal activity of functional status LEDS during booting
OK FAIL ONLINE Status Process
off on off 1 Module is in the power-up restart state; the FAIL
LED stays on briefly.
off off off 2 Module is initializing, and diagnostic tests are
running.
on off off 3 Module passed the diagnostics; the system boots.
on off on 4 Module is now up and running.
Table 10-4 Troubleshooting abnormal LED activity on modules
Diagnostic Signs Possible Problems Actions
• POWER A OK is not lit
• POWER B OK is not lit
• System is not receiving
power from Power A.
• System is not receiving
power from Power B.
1 Check Power A and Power B terminal connections.
2 Verify that power switches are on.
3 Check connections to power sources.
4 If system still does not operate, contact Juniper
Networks Customer Service.