After re-flowing IC3 for the third time I now have drive to the power supply! Had to go heavy on flux and hit it with a little higher temp than I was using initially. IC1 still has perfect output but I'm not seeing any drive at the output fet pads. Checked gate resistors and pulldowns and they all look good so I'm on to troubleshooting that. Getting there though!
Voltage builds to 1.24v before going into protect and dropping to 0.00v
(The solder bridge is currently connected on CON3)
(The solder bridge is currently connected on CON3)
Is it trying to draw excessive current when it starts to power up?
While monitoring the drive out of the driver IC (as it tries to power up), do you ever see any drive signal on either IC (check both high and low-side for both ICs)?
While monitoring the drive out of the driver IC (as it tries to power up), do you ever see any drive signal on either IC (check both high and low-side for both ICs)?
DCV black on Q37 emitter and red on base?
Same for Q38 but DCV on collector and base?
Check Q37 while it's out of the circuit.
Same for Q38 but DCV on collector and base?
Check Q37 while it's out of the circuit.
Q37 DCV with black on emitter and red on base reading -143.8v (with Q37 out of circuit)
Q38 collector to base 140.7v
Q37 tested good
Q38 collector to base 140.7v
Q37 tested good
- Home
- General Interest
- Car Audio
- Bass 8k not building power supply square wave