Cisco 1500 Series Micro Hubs

Field Notice: Cisco 1548U-DS Field Recall

June 15, 1998

Safety Field Alert

A recall of the Cisco 1548U-DS has been deemed necessary because of the potential of an internal heat sink to loosen and possibly reattach itself to the power supply or other conductive material in the chassis, causing a safety hazard.

Products Affected

caution Caution:?It is important to UNPLUG the Cisco 1548U-DS from the electrical source before attempting to come into contact with the unit, or before attempting to view the affected serial number on the chassis. AVOID touching and especially moving any part of the product except the power cord before unplugging. IF YOUR UNIT IS AFFECTED BY THE RECALL, DO NOT PLUG THE UNIT BACK INTO THE ELECTRICAL SOURCE.

The following products are affected:


Serial Number Range*

Date Range**


FAA02071156- FAA02181594

3/4/98- 5/12/98

* - The serial number is visible on the outside of the shipping box or on the bottom of the chassis.

** - This date range applies to units shipped from Cisco.


In some cases, the heat sink has been installed with the specified T4 heat conductive tape inverted. This can result in the detachment of the heat sink during shipment and it can reattach itself to the power supply or other conductive material in the chassis, posing a potential safety hazard to the customer.

Problem Description

There is a possibility that the internal heat sink on the Cisco 1548U-DSs (with the serial number and ship from factory date range indicated above) could become detached and move around inside the unit. In most cases, the unit will work correctly without the heat sink attached properly; however, the presence of such a large piece of conductive material moving around inside the product, which has an internal AC operated power supply, could violate the primary to secondary isolation safety requirements, which exist to prevent fire and shock hazards.


Do not attempt to remove the heat sink!

A Cisco representatitive will distribute a Recall Notification to the customer (either a reseller, distributor, or direct end-user) followed up by a phone call from Customer Service no more than one week later to verify that the notification was received and a no-charge replacement order was placed. If the customer has not yet placed the order, Customer Service will assist them over the phone.

Beginning June 15, 1998, customers may obtain replacement Cisco 1548U-DS systems at no charge through Cisco's Upgrades group.

Customers who purchased Cisco 1548U-DS systems from a reseller or distributor should contact Cisco, the reseller, or the distributor directly to arrange for replacement.

Customers who purchased Cisco 1548U-DS systems directly from Cisco and have verified that their Cisco 1548U-DS falls within the affected serial number range or ship from factory range can fill out the online Upgrade Form to arrange upgrading the Cisco 1548U-DS(s). If you have any questions concerning the the upgrade program, you can email the Upgrades group at

Physical Replacement of Cisco 1548U-DS

See the Cisco 1548 Micro Switch 10/100 Installation Guide for information.

For More Information

If you require further assistance, or if you have any further questions regarding this field notice, please contact the Cisco Systems Technical Assistance Center (TAC) by one of the following methods: