HP 650 Installation Manual page 45

If the Status LED remains orange at the end of the self-test or turns
orange during operation of the router, refer to chapter 3,
"Troubleshooting."
Unlit when the routing engine is not properly installed in module slot
1.
Pwr appears orange if two power supplies are installed and there is a
failure in one of them. To determine which power supply is faulty, open
the router door; the faulty power supply is the one for which the LED on
the power switch is not lit.
Fan appears orange when there is a failure in the cooling module. If the
Fan LED is lit during router operation, replace the cooling module.
Temp appears orange when the temperature exceeds specifications. If,
during operation of a router mounted in a cabinet, the Temp LED is lit
and the Fan LED is not lit, verify that the airflow around the router is not
restricted. The temperature where the router is installed should be
within the range specified in appendix C.
The Pwr, Fan, and Temp LEDs also appear orange momentarily at the
beginning of the self-test.
Description and Operation
LEDs and Buttons
2-5