Panasonic Generation Plasma Display Television Technical Manual page 72

1. Sound processing and adjustments are performed by IC2106. The two channel PWM audio output of
the IC is applied to the audio power amplifier IC2301. The PWM signals of the power amplifiers are
output to the right and left channel speakers for sound reproduction.
2. IC2303 converts the 15V source to 12V for connection to the audio power amplifiers.
3. The diode D2303 and transistor Q2301 monitor pin 5 of the power amplifiers for excessive current drain.
If a short circuit develops, transistor Q2301 goes into conduction and outputs a high to pin 118 of the
MPU, IC1100, triggering an SOS condition.
4. A short circuit of the 15V line causes the diode D2301 to go into conduction. As a result, the base
voltage of Q2301 becomes low and a high is output to the MPU to trigger an SOS condition.
12 Blinks SOS
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