Kicker SX900.4

[brandes.cm]

Channel 4 is out, the drive signal looks fine at Q431 and Q441. When checking the signal at Q442 and Q432 the signal loses the top half of the signal on one and the lower half on the other one.

Looking at a schematic for the IX402 seems close, but doesn't have the redundant drivers for each output device.

help is appreciated.

[Perry Babin]

Are the circuit board designations the same as the IX?

If not, you would need to list the designations for the corresponding parts.

Were the outputs in the board when you checked the drive signal?

[brandes.cm]

Q431 and Q441 are Q150 and Q151 on the IX schematic
Q442,Q432 are Q160 and Q161 on the IX schematic

No outputs were populated, I had them in and it seem to produce a clean sine wave and then the outputs failed after a few minutes.

[brandes.cm]

Placed 2 outputs and the signal looks fine. Maybe the first time I didn't have the clamps tight and the fets got hot and failed.

[Perry Babin]

You can't check the drive signals in class A/AB/B amps that use negative feedback (most all commercially available amps) without the outputs in the circuit.