Field Notice: FN63893 - N55-PAC-1100W PSU Silent Reload Failure - Replace on Failure
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Notice
THIS FIELD NOTICE IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTY OF MERCHANTABILITY. YOUR USE OF THE INFORMATION ON THE FIELD NOTICE OR MATERIALS LINKED FROM THE FIELD NOTICE IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS FIELD NOTICE AT ANY TIME.
Products Affected
| Affected Product Name | Description | Comments |
|---|---|---|
| N55-PAC-1100W | ^Nexus 5500 PS, 1100W, Front to Back Airflow | |
| N55-PAC-1100W-B | ^Nexus 5500 1100W AC Power Supply with Back to Front Airflow |
Defect Information
| Defect ID | Headline |
| CSCuf57615 | undefined |
Problem Description
A particular component failure in N55-PAC-1100W and N55-PAC-1100W-B power supply units (PSUs) can cause the entire 5596UP or Nexus 600x switch to reload.
All N55-PAC-1100W power supplies with a Part Number 341-0415-01 or 341-0415-02 are impacted. N55-PAC-1100W power supply with Part Number 341-0415-03 are not impacted.
All N55-PAC-1100W-B power supplies with a Part Number 341-0461-01 or 341-0461-02 are impacted. N55-PAC-1100W-B power supply with Part Number 341-0461-03 are not impacted.
Note: The previously published impacted Serial Number (S/N) range of "POG1746XXXX and below" still applies if the power supply Part Number is not 341-0415-03 or 341-0461-03. However, it is recommended that impacted PSUs be identified by Part Number instead of S/N, as detailed in the preceding paragraphs.
Background
The most common reason for the system reset is loss of power to the switch. Make sure the switch has dual power supplies connected to different power distribution units (PDUs) and power to the switch is stable.
This bug is seen on switches with redundant power supplies powered up and when one of the power supplies goes bad, which triggers the entire switch to reload.
Problem Symptom
A single PSU failure in a Nexus 5596UP or Nexus 600x switch might cause the entire system to reboot.
Workaround/Solution
If the Nexus 5596UP or Nexus 600x switch shows the problem mentioned in the Problem Symptom section and the power supply Part Number of the switch as mentioned in the Problem Description section, request a replacement of the power supply unit through the standard Return Material Authorization (RMA) process using normal service support channels.
See the How to Identify Affected Products section for instructions on how to view the version of in-service product.
How to Identify Affected Products
To identify the affected products, please run the below commands and check for the Power Supply Part Number as mentioned in the Problem Description section.
5596B# show sprom powersupply 2 | egrep Product|Part|Serial Product Number : N55-PAC-1100W Serial Number : POG151350GJ Part Number : 341-0415-01 Part Revision : B0 5596B#
Revision History
| Version | Description | Section | Date |
| 10.5 | Updated the Workaround/Solution Section with information about using the standard RMA process | — | 2024-APR-16 |
| 10.4 | Updated the Workaround/Solution Section and Removed the Upgrade Program Section | — | 2021-MAY-24 |
| 10.3 | Updating the replacement PID in the Umpire Order Form | — | 2018-MAR-02 |
| 10.2 | Minor Edit - Changed wordings in Workaround/Solution section | — | 2018-JAN-19 |
| 10.1 | Updated Umpire Dates | — | 2017-NOV-30 |
| 10.0 | Migration to new field notice system | — | 2017-OCT-10 |
For More Information
For further assistance or for more information about this field notice, contact the Cisco Technical Assistance Center (TAC) using one of the following methods:
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