30 Watt subwoofer amplifier circuit

This circuit use IC TDA1004A to main operation .IC is very nice and durable if used properly and correctly, by the way supply the correct voltage , don't supply more voltage than 20 volts, because it can damage the IC. This circuit suitable for subwoofer speakers, but this amplifier  is mono.See schematic and troubleshooting below :


If the circuit above not working , posible cause is on :
  • Supply voltage.
  • IC Damaged or installation inverted.
  • Component damaged .
  • Installation components inverted.
  • Line break PCB.
  • Input not connected or input connect to ground.
  • Output speaker not connected.