the amp has an issue where it plays audio fine at 12 volts but at 14 volts the audio cuts out. When I was poking around I noticed the 7912 regulator is only putting out -7.7 volts. Im having trouble figuring out why. I replace the regulator with no change
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So the amp power up fine. All rail voltages are correct but I'm not getting any switching and I can't figure out why.
Does no load or loaded make a difference?
Before installing the outputs, did you check for the proper operation of the TL072? I've never done it on this board but connecting a 10k resistor across terminals of 1 and 2 (or 6 and 7 if they're using the other half of the TL072) should tell you if the TL072 is working properly.
You have a badly damaged via (can be seen in the original post).
Is the drive good out of the LM211 going from 0% to 100% duty cycle when driven hard?
Before installing the outputs, did you check for the proper operation of the TL072? I've never done it on this board but connecting a 10k resistor across terminals of 1 and 2 (or 6 and 7 if they're using the other half of the TL072) should tell you if the TL072 is working properly.
You have a badly damaged via (can be seen in the original post).
Is the drive good out of the LM211 going from 0% to 100% duty cycle when driven hard?
You will have to use your scope. Letting the scope ground through the 12v power supply ground should be sufficient. If it's too noisy, use the secondary ground.