hi.
I am working on a DD Z2B in its output section. After it arrived at the workshop, I replaced the 28x 24n50f, 28x 33ohm gate resistors, irs2184s, 4x tc4452vat, 18v zener diodes, 7812 2A, checked resistors and everything was ok.
I started the amp and it blew up one side almost completely.
What could be causing this problem?
thank you.
I am working on a DD Z2B in its output section. After it arrived at the workshop, I replaced the 28x 24n50f, 28x 33ohm gate resistors, irs2184s, 4x tc4452vat, 18v zener diodes, 7812 2A, checked resistors and everything was ok.
I started the amp and it blew up one side almost completely.
What could be causing this problem?
thank you.
I checked the J111 transistor that belongs to SD and the MUTE circuit, all the components seem to be fine.
I have also tried to turn on only the output board with lower external voltages (+/- 24v) but I think it has a protection circuit against low rail voltage (image attached) that I don't know how I should "fool" it and be able to start safely....
I have also tried to turn on only the output board with lower external voltages (+/- 24v) but I think it has a protection circuit against low rail voltage (image attached) that I don't know how I should "fool" it and be able to start safely....
Attachments
When you used low voltage, did you remove the rectifiers and power up the board normally with the only difference being that the output rails had only ±24v?
With ±24, do you get the 12v for the low-side drive?
What's the DCV on the SD pin of the driver IC?
At this point, which parts are out of the board?
What's the DCV on the SD pin of the driver IC?
At this point, which parts are out of the board?
Yes, I power 12v with another external source (I'm lucky to have 6 power supplies in the workshop) I have not checked the SD voltage, since, when I checked J111 that it was OK, I did not give it any more importance. When I performed those tests, everything was in place, never part outside the PCB. but I was never able to measure PWN on the output because the amplifier was in protection due to the rail undervoltage protection circuit.
You shouldn't need to supply 12v to the low-side supply on the driver IC.
It had blown output FETs. Did you replace them all?
It had blown output FETs. Did you replace them all?
Yeah. They are all new. from a batch that I have already used in other amplifiers and they work perfectly.
Do you have the low-side 12v without an external supply?
What protection do you see that's shutting down the output under low-voltage?
What protection do you see that's shutting down the output under low-voltage?