Cisco CVA120 Series Cable Voice Adapters

Field Notice: CVA122 and CVA122E Failure in Rare Cases Due to Defective Capacitors

October 7, 2002

Products Affected


Top Assembly

Part Number








Problem Description

A component defect in capacitors C75 and C76 may cause one or both of these capacitors to short, which results in a power shutdown failure.


The failing units show cracked, burnt, or shorted capacitors at C75 and C76. The defective capacitors prevent the modem from powering up and coming online. The function of C75 and C76 is to provide a voltage reference point (threshold level) for the voltage protectors U26 and U27 in the voice circuit. These are decoupling capacitors and do not shunt current. They are not in play in the event of a surge or overvoltage. Surge and overvoltage are handled elsewhere in the CVA122/E.

The problem has been tracked to a limited number of defective capacitors supplied by the component vendor and used during a specific manufacturing period. Therefore, the problem should only affect those modems that were built during or around September 2001.

Problem Symptoms

The modem does not power up and a burnt smell may emanate from the modem at the time of failure because of the defective capacitor.


There is no workaround. Submit a return materials authorization (RMA) for any unit that has failed.

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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