Upon Routing-Engine reseat or replacement the Control-board might be stuck in  State 'Present' while the Routing Engine is fully operational and online.


re0> show chassis environment cb 

CB 0 status:

 State           Present Master

 Bus Revision        247

 FPGA Revision       267

CB 1 status:

 State           Online Standby

 Intake A Temp Sensor          20 degrees C / 68 degrees F       

 Intake B Temp Sensor          19 degrees C / 66 degrees F       

 Exhaust A Temp Sensor          22 degrees C / 71 degrees F       

 Exhaust B Temp Sensor          24 degrees C / 75 degrees F       

 Middle Temp Sensor           25 degrees C / 77 degrees F 



re0> show chassis routing-engine 

Routing Engine status:

 Slot 0:

  Current state         Master

  Election priority       Master

  Temperature         28 degrees C / 82 degrees F

  CPU temperature       28 degrees C / 82 degrees F

  DRAM           119023 MB (128325 MB installed)

  Memory utilization      7 percent

<..>

Routing Engine status:

 Slot 1:

  Current state         Backup

  Election priority       Backup

  Temperature         26 degrees C / 78 degrees F

  CPU temperature       26 degrees C / 78 degrees F

  DRAM           120615 MB (128325 MB installed)

  Memory utilization      6 percent

Run this command on backup RE to bring the CB online.
Note that, this command cannot be run on master CB/RE.

> request chassis cb slot <slot> online

This issue is fixed via PR: 1747567