Sony CF-270L Audio Circuit

The Sony CF-270L printed circuit board can accumulate dust through the back grille in the case. Luckily, it has hinges on one side and swings out for servicing purposes.

PCB - Component Side

Power Output Transistors

Audio Transformer

Switch

The circuit reconfiguration switch, also known as "the long switch", reconfigures the circuit between record and playback modes. If your unit is producing feedback whistling, and crackling sounds, then this switch may require cleaning with a good electrical contact cleaner.

Potentiometers

On this unit, the tone, bass and volume potentiometers required cleaning with a contact cleaner because they were producing crackling noises.

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