Okay, the waveforms all look good.Frequency calculates to 33.3Khz and the amplitudes are what I would expect. Be sure to probe all mosfet gate pads for the rectangular wave. This will insure that all mosfets gates will be connected and no broken/crack traces or open/ out of value 47 ohm gate resistors. This is a common problem, when a mosfet gate is open circuited it will cause the mosfet/s to fail. I suspect that the mosfets that failed was due to this condition.
U02-TL494 is the PWM for the auxiliary power supply and supplies the operating voltage (8Vdc?) for the DAP screen(Display board). In the case of U01 the duty cycle is a ~50% duty cycle.
The link might be useful. Perry Babin will have a good explanation in his tutorial, which I highly recommend. Basic Car Audio Electronics
What Is Duty Cycle? | Fluke
U02 is roughly a 20% Duty Cycle. If you install the DAP it should light up. Always power down before you attach any board to the main board.
You can install the mosfets now. Be sure the ohm readings are the same across the 1-3 pins, before you power up.
U02-TL494 is the PWM for the auxiliary power supply and supplies the operating voltage (8Vdc?) for the DAP screen(Display board). In the case of U01 the duty cycle is a ~50% duty cycle.
The link might be useful. Perry Babin will have a good explanation in his tutorial, which I highly recommend. Basic Car Audio Electronics
What Is Duty Cycle? | Fluke
U02 is roughly a 20% Duty Cycle. If you install the DAP it should light up. Always power down before you attach any board to the main board.
You can install the mosfets now. Be sure the ohm readings are the same across the 1-3 pins, before you power up.
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