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Cisco ONS 15454 Series Multiservice Provisioning Platforms

Field Notice: ONS 15454E-FTA-48V Thermal Issue on the Fan Tray Controller


Revised November 11, 2005

October 26, 2004


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

Product Top Assembly Part # Comments
15454E-FTA-48V
800-14725-04
The affected 15454E FAN TRAY CONTROLLER number is 800-08435-02
15454E-FTA-48V=
800-14725-04
The affected 15454E FAN TRAY CONTROLLER number is 800-08435-02

Problem Description

The referenced Fan Tray Assembly (FTA) may stop operating if its power is cycled while operating at or above 50 degrees Celsius system ambient temperature.

Background

Through Ongoing Reliability Testing (ORT) it has been determined that the output of a specific component on the FTA's Fan Control Board (FCB) may "latch-up" if power to the component is cycled, for example, on-off-on while the device is operating in a system ambient temperature at or above 50 degrees Celsius. The output of the specific component is used to control the rotational speed of the fans in the FTA by providing a Pulse Width Modulated signal to power devices that are used to drive the fans. If the output of the component latches up the fans will stop spinning.

This component issue has been isolated to parts from a single specific vendor. Switching to parts from a different qualified vendor solves the potential problem.

Problem Symptoms

With the unit at or above 50 degrees Celsius, if system power is removed and the TCC is removed, or the fan tray is removed then replaced, the 555 timer could lock up.

Power to the FTA may be cycled by any of the following means:
Simultaneously cycling power at both Battery A and Battery B feeds that power the associated Shelf Assembly (SA), simultaneously removing and reinstalling both TCCs or removing and reinstalling the FTA itself. If the component "latch-up" condition described above occurs, the fans in the FTA will stop spinning.
In response to this condition a "FAN FAIL" alarm will be raised in CTC and the "FAN FAIL" indicator lamp on the front panel of the FTA will be illuminated.

Workaround/Solution

If the component "latch-up" condition described above occurs, it may be cleared by power cycling the FTA by removing and reinstalling it in its associated shelf assembly.

Temporarily removing and reinstalling the FTA is non-service affecting.

In order to prevent the described condition from occurring, the affected component on the fan controller board in the associated FTA will need to be replaced.

How To Identify Hardware Levels

To determine the Part Number, Hardware Revision and Serial Number of your 15454E-FTA-48V Fan Tray Assembly:

Open CTC.

From the Shelf View, select Inventory

From the Inventory tab, locate the 15454E-FTA-48V Assembly and compare the information from the Inventory tab against the Products Affected section above.


( Click image for larger view)

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:

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