KDC-309A: output became intermittent then died completely. Anti theft light still working so power supply connection not a problem. Suspect internal power supply. Is this a regular and known defect? Any advice appreciated please.

Martyn, August 2008

There are usually two battery supplies to a radio. One via the ignition for running the radio. The other as a permanent feed for the radio memory etc. so it might be the ignition feed failing/failed ...possibly a dodgy connection , loose fuse etc

Check with a multi-meter or test lamp.
see
http://www.tehnomagazin.com/Auto-radio-car-connector/KENWOOD-Car-Radio-Wiring-Connector.htm

RegWorts, August 2008