Cisco XR 12406 - Manual (Page 142)

Chapter 4 Troubleshooting the Installation
Troubleshooting a DC Power Subsystem
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Cisco XR 12406 Router Installation Guide
OL-13831-01
Step 4 Power off the PEM circuit breaker switch and check the DC power source.
• Check the DC power wires from the power source to the router.
– Verify that the power wires are fastened securely at the PDU and the DC
source.
– Verify that the power wires are not worn or damaged. If the insulation
appears cracked or broken, have the power wires replaced.
• Make sure that the DC power source circuit breaker is on, and that it has the
proper current rating.
• Verify that each PEM in the router is attached to a separate DC power source.
• Power on the PEM circuit breaker.
– If the PEM INPUT OK LED goes on, go to Step 6 .
– If the PEM INPUT OK LED remains, go to Step 5 .
Step 5 Remove the PEM and insert it in the second bay in the router, or into a bay on
another Cisco XR 12406 router.
• If the INPUT OK LED remains off, the PEM is faulty and needs to be
replaced.
• If the INPUT OK LED goes on, the input portion of the PEM is working
normally, go to Step
6 .
Step 6 Is the OUTPUT OK LED on?
• If yes, the power source is good and the PEM is operating normally.
• If no, and there is no other system activity (blower module is off; line cards
are unpowered), the PEM is fault. Replace the PEM.
• If no, but the blower module is operating, it means all internal DC voltages
are within tolerance. Suspect a faulty OUTPUT OK LED.
– Use the show environment command to check the voltages on each card.
The blower module uses –48 VDC.
Note In a Cisco XR 12406 router with two power supplies, the output power
from the second power supply is adequate to maintain router operation.