Troubleshoot the SCB

To troubleshoot the SCB, follow these guidelines:

• Periodically check the alarm LEDs and the LCD on the craft interface. If the SCB is not functioning properly, it might send spurious error messages to the Routing Engine (indicating incorrectly that system components are malfunctioning, for example). These messages can appear on the LCD.
• If all four LEDs on the SCB faceplate are on, but dimly lit, the SCB is probably not seated properly. Tighten the captive screws at the top and bottom of the SCB card carrier. For more information about the LEDs, see SCB Components.
• If the green RUN LED on the SCB is not blinking, the SCB processor is not functioning normally. The SCB might not be connected properly to the backplane. Try tightening the screws at the top and bottom of the SCB card carrier. If that does not work, try reinstalling the SCB.
• When the Routing Engine is removed, the SCB enters a warm shutdown mode and continues forwarding data for a limited time using a frozen forwarding table. (The default time limit is determined by a timer in the SCB.) If the Routing Engine is replaced during the warm shutdown period, the SCB unfreezes its forwarding tables and resumes normal functioning. Otherwise, the SCB shuts itself down after the time limit expires.