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.
| Affected Product Name | Description | Comments |
|---|---|---|
| N540-6Z18G-10TS50= | Screw and torque kit for Beagle | |
| N540-6Z18G-1TS10= | Screw and torque kit for Beagle | |
| N540-6Z18G-20TS2C= | Screw and torque kit for Beagle | |
| N540X-4Z14G2Q-D | NCS540 14x1G + 4x1/10G + 2x10/25G Dual-DC iTEMP Conf-Coat | |
| N540X-6Z18G-SYS-D | NCS540 18x1G SFP + 6x1/10G SFP+ Dual DC iTEMP Conformal Coat |
| Defect ID | Headline |
| CSCwq07458 | PABU: NCS540: N540X-6Z18G-SYS-D and N540X-4Z14G2Q-D: Add insulative sticker around the power connector and add insulator to conceal exposed screw. |
A limited number of Cisco Network Convergence System (NCS) 540 Series Routers with Product ID N540X-6Z18G-SYS-D and N540X-4Z14G2Q-D may fail to power on when exposed to a Common Mode Surge Event greater than 4 kV. A common mode surge event occurs when a sudden voltage spike simultaneously affects both the positive and negative lines with respect to ground, often due to external factors such as lightning strikes or electrical switching disturbances.
A manufacturing process deviation has affected a specific batch of Cisco N540X-6Z18G-SYS-D and N540X-4Z14G2Q-D routers, resulting in a missing screw assembly that connects the Common Mode Surge protector to the ground. The issue has been rectified through corrective actions, and all new devices that are now shipping are assembled correctly. The functionality of the routers is not impacted for any voltage less than 4KV Common Mode Surge.
The impacted routers might become unresponsive if subjected to Common Mode Surge of 4kV.
Solution
To determine if a serial number is affected, see the Serial Number Validation section of this field notice. Cisco is offering the screws and accessories kit.
Cisco recommends properly installing the screws so that the routers can withstand 4KV Common Mode Voltage. The screw location is on the front panel of the router, as shown in the picture. Only one screw is required per affected device. Cisco recommends using only the Cisco-provided screwdriver, which is set to deliver a maximum torque of 0.5Nm.

The affected router must be powered off during in the screw installation.
The following table provides various combination of screws quantity and Torque Screw drivers. Once the impacted quantity of devices is determined from the Serial Number Validation section of the field notice, the Product ID with appropriate Screw quantity and accessories to be chosen. Please contact TAC to order any of the below listed PIDs based on quantiy of Screws needed.Cisco will ensure the required quantity is delivered to the specified location.
| Product ID | Screw Quantity | Details |
|---|---|---|
| N540-6Z18G-1TS10= | 10 | The kit contains 10 screws and a torque screwdriver. |
| N540-6Z18G-10TS50= | 50 | The kit contains 50 screws and 10 torque screwdrivers. |
| N540-6Z18G-20TS2C= | 200 | The kit contains 200 screws and 20 torque screwdrivers. |
Affected routers that fail to power on after being subjected to 4kV Common Mode Surge Voltage can be returned to Cisco as part of the Return Materials Authorization (RMA) process.
To determine if a router is affected, please follow the instructions provided in the Serial Number Validation section of this field notice.
| Version | Description | Section | Date |
| 1.0 | Initial Release | — | 2026-APR-02 |
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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