Rockford Fosgate Punch Power 250.2 PC-0767-J

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I have an issue going on after replacing the outputs and drivers in both channels, three of the source resistors and Q316 & 317 (left channel)

I am using drawing No. SCH-0767-J rev.D

When the amp is driven to moderate levels, playing music, bridged or right channel only, loaded with a four ohm speaker, the amp will protect briefly. I see pin 1 of the LM339 drop voltage as a result of pin 7 dropping below pin 6. I'm not finding the defective part causing this and it doesn't seem to do it on a 4 ohm resistive load.

What am I missing?
No, I replaced outputs and drivers in both channels.

I checked all source resistors, but only replaced three, in the left channel that go to the 540's.

When setting the bias, I measure 1mV across two of each group of three source resistors, but one of each group of three is lower, ~.6mV or so both channels. How sensitive is it toward a mismatch? The 540's are from the same batch and the 9540's are same batch, both channels.
The over-current protection current uses the voltage drop across the source resistors to determine when the amp should shut down. You seemed to be concerned about the difference in voltage across the source resistors. That's why I suggested checking the voltage across the source resistors at higher current levels.

Pin 7 of the 339 is driven to ground by one of the other 4 outputs of the 339 via D4. When there is a fault detected (low voltage, thermal, high voltage), the delay cap is discharged and the delay begins again when the fault clears.
The B+ and remote lines were staying steady. The amp does mute (pin1 of the 339 goes to 0V), at ~11.2VDC on B+.

I had noise on the left channel that I didn't notice before. I touched up solder on R389 and that fixed that.

Now after doing that, I can't get the amp to mute like before bridged or right channel only. When driving the amp moderately with audio and a 4 ohm speaker, pin 1 of the 339 does drop as low as ~5.7VDC, but it does not mute anymore. Driving a 4 ohm resistor with audio, pin 1 stays steady at ~16.7VDC.

Here are the measurements across the source resistors as of now. First measurement is at idle, no input signal. Second & third measurements are with ~5VAC across the 4ohm dummy load in mVDC and mVAC respectively.

Left Channel 9540's
RM1: 1.1mVDC 17.9mVDC 23.0mVAC
RM2: 1.9mVDC 20.9mVDC 26.9mVAC
RM3: 1.6mVDC 19.0mVDC 25.6mVAC

Left Channel 540's
RM4: 1.2mVDC 20.4mVDC 28.0mVAC
RM5: 1.5mVDC 22.7mVDC 30.6mVAC
RM6: 1.5mVDC 23.4mVDC 31.4mVAC

Right Channel 9540's
RM7: 1.5mVDC 20.0mVDC 25.5mVAC
RM8: 1.7mVDC 20.5mVDC 26.6mVAC
RM9: 0.9mVDC 16.9mVDC 24.0mVAC

Right Channel 540's
RM10: 0.9mVDC 21.0mVDC 29.3mVAC
RM11: 1.1mVDC 22.4mVDC 30.8mVAC
RM12: 1.1mVDC 22.6mVDC 30.8mVAC

LM339 measurements at idle, no signal.
1: 16.720
2: 5.400
3: 17.870
4: 0.276
5: 2.595
6: 4.990
7: 5.770
8: 4.160
9: 4.990
10: 4.990
11: 7.840
12: 0.000
13: 5.400
14: 5.400

I'll have to capture measurements of the 339 with amp driving a speaker later to show the output pins changes.
I was not getting the amp to mute with my 4 ohm woofer but when I changed it out to a 2 ohm woofer wired only to the right channel it mutes easily. It does not when wired to the left channel.

Here are the measurements on the 339 I captured while it was muting.

1: as low as 0
2: 4.362
3: 17.23
4: 0.209
5: 2.560
6: 4.989
7: as low as 1.6
8: 4.16
9: 4.989
10: 4.989
11: 7.85
12: 0.00
13: 4.365
14: 4.365

The regulated voltages on U301/401 & U302/402 are about +/- 16.5V when normal and about +/- 17.3V when muted. B+ and remote remain stable as the amp mutes.
Unless I am doing something wrong, the only thing I suspect is a defective 339. But if it were in fact defective I would expect the amp to mute when driving either channel.

I have checked all resistors around the 339 in circuit and they are measuring ok.

Maybe the voltage drop on pin 13 is happening faster than I can see on my meter?
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