This audio source generator with single-chip microcomputer, structure and General alarms are the same, most power amplifier using single chip integrated circuit amplifier circuit is simple and high efficiency. 12V power supply first with the core booster circuit TL494 and +38V the switch the secondary of a transformer for a stable voltage, power to power amplifier chip.

Because the chip has a serious crack, don't see models, mapping its surface area circuit judge. ⑦ (13) feet +VCC, h, (15) foot-Vcc, ① ④ feet grounded, ③ signal input volume potentiometer foot Center tap, II foot external 470 Ohm resistor with negative feedback, 47 μg F/50V Capacitance to ground (14) feet speakers, judging from its application circuit, this chip is TDA7294. Removing bad manifold block, electricity measuring +38V correctly, say it integrated block has nothing to do with the power supply. After using new TDA7294 substitution, the volume is not adjusted, indicating volume potentiometers are bad, manifold block damage is likely to be caused by the input signal is too strong. After its replacement, adjust the volume to normal, loading test, stentorian, adequate power, and troubleshooting.