I am need of assistance for a HCCA 3000.1D SPLX. I have a dead amp. I have replaced the power supply FETs and gate resistors. The 3525 is shutdown.(pin 10 high, 5v) I found that one of the 2N700 was open, I replaced both of them.
With pin 10 lifted, no voltage on it. The resistor pad now has 12v and then pulls down to 6.8v
Relanding pin 10 now, and placing resistor back on the board.
Relanding pin 10 now, and placing resistor back on the board.
Did the softstart cap charge?
Lifting pin 10 should not have affected the fan, as far as I know, especially if the IC produced no output.
Lifting pin 10 should not have affected the fan, as far as I know, especially if the IC produced no output.
If pin 10 is at ground (or less than about 1/2v), pin 8 should charge the SS capacitor. Can you remove the capacitor (or lift pin 8) to see if the voltage will come up on that pin?
It's charged internally. The only thing that can prevent it (if you have 5v out) is pin 10 being too high. If pin 10 is at 0v (resistor pulling it high, out of the circuit), the IC would appear to be defective.
I had soldered pin 10 and the resistor back in the circuit. I just pulled pin 10 up again and checked pin 8, pin 8 came up to 4.9v with both 8 and 10 pins pulled off the board.
With that being said, I now have PWM on power supply FETs.
With that being said, I now have PWM on power supply FETs.
Output pulses?
When you have to lift pins like this and need to resolder them, possibly temporarily, just bridge between the pad and pin so you don't fatigue the pin and have it break off. After the repair is done, you can solder it properly.
When you have to lift pins like this and need to resolder them, possibly temporarily, just bridge between the pad and pin so you don't fatigue the pin and have it break off. After the repair is done, you can solder it properly.
No low side output signal on FET pads.
Do the outputs need to be in for this amp to get a signal?
Do the outputs need to be in for this amp to get a signal?