With terminal 2 of the 20957 high, it doesn't seem like the amp is in protect.
Have you tried operating all of the pots and switches through their entire range with a signal source connected to see if that allowed a square wave to reach the 20957 pin 3?
Have you tried operating all of the pots and switches through their entire range with a signal source connected to see if that allowed a square wave to reach the 20957 pin 3?
It goes into protect with speaker plugged in. With no speaker it's just the clip light. I moved the pots around then tested to see and still no signal on pin 3 of the 20957s. Should the signal be on all 3 op amps? It's only on the one ic2. And there is 4 outputs on ic2 and only signal on 3 of them.
I'm not sure what the circuit is but I'd expect most of the op-amps in the audio circuit to have audio on most of the outputs. Many times, an intermittent connection on a switch or pot can prevent audio from passing through the amp.
Does pin 7 of the microcontroller connect to ground (0 ohms)?
Does pin 7 of the microcontroller connect to ground (0 ohms)?
Microcontroller is the logic IC that takes in various inputs (from protection, etc.) and sends signals to various circuits in the amp (various LED indicators, output IC, power supply drive...).
How many 20957s in the amp?
Copy and paste the following list and fill in the blanks. If there is no blank space after the colon, add one between the colon and the numbers you enter. It makes it much easier to read. DC voltage on all terminals of that IC?
Pin 1:
Pin 2:
Pin 3:
Pin 4:
Pin 5:
Pin 6:
Pin 7:
Pin 8:
Pin 9:
Pin 10:
Pin 11:
Pin 12:
Pin 13:
Pin 14:
Pin 15:
Pin 16:
Pin 17:
Pin 18:
Pin 19:
Pin 20:
Copy and paste the following list and fill in the blanks. If there is no blank space after the colon, add one between the colon and the numbers you enter. It makes it much easier to read. DC voltage on all terminals of that IC?
Pin 1:
Pin 2:
Pin 3:
Pin 4:
Pin 5:
Pin 6:
Pin 7:
Pin 8:
Pin 9:
Pin 10:
Pin 11:
Pin 12:
Pin 13:
Pin 14:
Pin 15:
Pin 16:
Pin 17:
Pin 18:
Pin 19:
Pin 20:
Pin 1: 4.8
Pin2: 4.5
Pin 3: 4.4
Pin 4: 4.8
Pin5: 0.8
Pin6: 2.3
Pin 7: 0.9
Pin 8: 4.7
Pin 9: 0
Pin 10: 0
Pin 11: 0
Pin 12: 0
Pin 13: 4.7
Pin 14: 0.8
Pin 15: 3.8
Pin 16: 2.3
Pin 17: 4.3
Pin 18: 2.1
Pin 19: 0
Pin 20: 0
Pin2: 4.5
Pin 3: 4.4
Pin 4: 4.8
Pin5: 0.8
Pin6: 2.3
Pin 7: 0.9
Pin 8: 4.7
Pin 9: 0
Pin 10: 0
Pin 11: 0
Pin 12: 0
Pin 13: 4.7
Pin 14: 0.8
Pin 15: 3.8
Pin 16: 2.3
Pin 17: 4.3
Pin 18: 2.1
Pin 19: 0
Pin 20: 0
I've had to use a 'phone a friend'. I'll get back to this if/when I hear from him.
If anyone else can help, feel free.
If anyone else can help, feel free.