This document explains why we see multiple Over temperature alarms on LC2101 card and how to fix it

In message logs, we can see multiple logging for over temperature alarms on FPC:

Dec 21 03:51:43 CHASSISD_SNMP_TRAP6: SNMP trap generated: Over Temperature! (jnxContentsContainerIndex 7, jnxContentsL1Index 1, jnxContentsL2Index 0, jnxContentsL3Index 0, jnxContentsDescr FPC: JNP10K-LC2101 @ 0/*/*, jnxOperatingTemp 91)

Dec 21 03:51:58 CHASSISD_SNMP_TRAP6: SNMP trap generated: Temperature back to normal (jnxContentsContainerIndex 7, jnxContentsL1Index 1, jnxContentsL2Index 0, jnxContentsL3Index 0, jnxContentsDescr FPC: JNP10K-LC2101 @ 0/*/*, jnxOperatingTemp 58)

Dec 21 03:52:13 CHASSISD_SNMP_TRAP6: SNMP trap generated: Over Temperature! (jnxContentsContainerIndex 7, jnxContentsL1Index 1, jnxContentsL2Index 0, jnxContentsL3Index 0, jnxContentsDescr FPC: JNP10K-LC2101 @ 0/*/*, jnxOperatingTemp 91)

Dec 21 03:52:28 CHASSISD_SNMP_TRAP6: SNMP trap generated: Temperature back to normal (jnxContentsContainerIndex 7, jnxContentsL1Index 1, jnxContentsL2Index 0, jnxContentsL3Index 0, jnxContentsDescr FPC: JNP10K-LC2101 @ 0/*/*, jnxOperatingTemp 58)

We can see the temperature is constantly fluctuating from 58 degrees to 91 degrees a jump of 30 degrees in 30 seconds which is highly improbable.

The ambient temperature found to be  around 23.0 C in front of the router, 26.3 C at the back of the router, and it doesn't look like anything was blocking the airflow.This meant there is no issue in site.

A component temperature cannot jump up and down by 30C in seconds. This can be a good implication of temperature sensor not working correctly.

This may be a mix of "FPC 0 EA2_HMC0 Logic die" and "FPC 0 EA4 Temp Sensor" being faulty.

Solution:Our suggestion is to replace the faulty FPC.