even without the Q625 Q626 excitators there is no PWM on the TL 494 pin 8 and 11 with the oscilloscope it is dead rrrrr
Still no base signal on the driver transistors?
Do you have a sawtooth waveform on pin 5 of the 494?
Do you have a sawtooth waveform on pin 5 of the 494?
PZTA56.
For some reason, the 339 wasn't happy with something. Copy and paste and fill in the DCV for the 339 pins:
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:
For some reason, the 339 wasn't happy with something. Copy and paste and fill in the DCV for the 339 pins:
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: