A limited number of 15327 OC3-4 cards (See Serial Number List) may suffer impaired performance when the system ambient operating temperature is at or below -20 degrees Celsius. This performance impairment is attributable to a timing component utilized on the referenced card.
It has been determined that a specific lot of Voltage Controlled Crystal Oscillator (VCXO) modules, manufactured by a single component vendor, may contain an internal anomaly that adversely affects their functional performance at the aforementioned very low system operating temperature extreme. While exposed to the very low system operating temperature extreme, the output of these VCXO modules may no longer operate within their parametric limits.
Operating the referenced cards from the above Serial Number List in an environment where the system ambient temperature is at or below -20 degrees Celsius may precipitate the following symptoms:
Contact the TAC as listed below to request replacment of any boards listed on the Serial Number List with a revision level of -02.
Do not operate the referenced cards in a system ambient temperature that is at or below -20 degrees Celsius. If this low system ambient operating temperature extreme cannot be avoided and will persist for a lengthy period of time, the associated system's Fan Tray Assembly (FTA) can be removed as a temporary field expedient until the referenced card(s) can be replaced. Removal of the FTA may allow the system internal temperatures to remain high enough to avoid the problem and associated symptoms described above.
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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