4.2. Power AMP (AMP PCB)
No audio output.
Protection is activated.
Is the power transistor open or short circuited?
DHCT-A3 / DHCT-C3
Is the emitter resistor of the power transistor open?
0.47Ω
Is the base resistor of the power transistor open?
47Ω
Is the trimmer potentiometer between the base of the
power transistor open?
300Ω
Are any other transistors faulty?
Are any other resistors faulty?
Turn on the power and check that the voltage of each part is correct and that there is an idling current.
Replace the power transistor.
Replace the transistor.
Replace the resistor.
Replace the emitter resistor.
Replace the base resistor.
Replace the trimmer potentiometers.
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
YES
s
s
s
105
