Juniper MX2008 Hardware Manual page 492

RCB LEDs—For the Control Board portion of the RCB, there is a set of bicolor LEDs, labeled OK/FAIL,
LINK, ExtClk-0, ExtClk-1, BITS, and GPS. For the Routing Engine portion of the RCB, there are three
LEDs, labeled ONLINE, MASTER, and OK/FAIL. These LEDs on the faceplate indicate the status of the
RCB.
NOTE: Even though the RCB are combined into one unit; the LED functionality is separate
for the Control Board and Routing Engine.
AC delta or wye PDM LEDs—One LED for each input terminal block indicating the input feed status.
DC PDM LEDs—One LED on each PDM next to each of the nine –48VDC power feeds indicates the
status of that PDM's incoming power.
AC or DC PSM LEDs—Four LEDs, labeled PWR OK, FAULT, INP0, and INP1, on each PSM faceplate
indicate the status of that PSM.
SEE ALSO
MX2008 Craft Interface Description | 43
Troubleshooting the MX2008 Host Subsystems | 510
Troubleshooting the MX2008 MPCs | 512
Troubleshooting the MX2008 MICs | 511
Troubleshooting the MX2008 Cooling System
Problem
Description: The following alarms, LEDs, and other conditions indicate a problem with the cooling system:
A red alarm indicates that temperature of the router exceeds the maximum ("temperature hot") threshold.
Automatic shutdown of the power system was caused by the temperature of the router exceeding the
maximum ("temperature hot") threshold.
A red alarm indicates that a fan failed.
A yellow alarm indicates that the router temperature exceeds the "temperature warm" threshold.
A yellow alarm indicates that one of the fan trays was removed.
One or more fans in a fan tray function at full speed. The RCB constantly monitors the temperatures
detected by sensors on the midplane and router components, adjusting the speed of the fans as necessary.
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