Ampeg BA115HP Output and crackling/static

[x-pro]

Have output and crackle/static thru speaker output. No crackle thru headphone output but seems to be reduced volume.

Removed Q9, jumped drain to source,, headphones have output with or without speaker connected. Speaker has no output with or without headphones connected

This is so good!
At first there was some sound and now there is none at all.

[x-pro]

I guess you mean there may be DC at the headphone out jack of his phone?

It doesn't matter anymore. The amplifier's not working or the speaker.

[x-pro]

It is possible that frequent turning over of the PCB has caused some wires to break and break off.

[g1]

Removed Q9, jumped drain to source,, headphones have output with or without speaker connected. Speaker has no output with or without headphones connected

Leave Q9 out and keep jumper there. Remove Q6. Still no sound at speaker?

[ca7922303]

Leave Q9 out and keep jumper there. Remove Q6. Still no sound at speaker?

Q9 out, d/s jumpered, removed Q6, no sound at speaker. Headphones have output with or without speaker connected.

[g1]

Set up input signal and controls as stated in 'Test Point Conditions' at bottom of power amp schematic (07S457-XX).
Measure AC volts at TP12 and TP10.

[ca7922303]

Set up input signal and controls as stated in 'Test Point Conditions' at bottom of power amp schematic (07S457-XX).
Measure AC volts at TP12 and TP10.

TP10(0.13vac)
TP12(0.08vac)

[g1]

Under those same test conditions, do you have around 1VAC at headphone jack?

[x-pro]

What is the DC voltage in TP11 ?

[ca7922303]

Under those same test conditions, do you have around 1VAC at headphone jack?

(0.22vac) under same test conditions

[ca7922303]

What is the DC voltage in TP11 ?

TP11(-0.88vdc) no signal applied

[g1]

Under those same test conditions, do you have around 1VAC at headphone jack?

(0.22vac) under same test conditions

Set up again with test conditions stated on schematic, 170mV 1Khz at input jack, gain and vol. full up, tones at '5'.
What are AC voltages at TP's 1 to 5, and TP8 ?

[ca7922303]

Set up again with test conditions stated on schematic, 170mV 1Khz at input jack, gain and vol. full up, tones at '5'.
What are AC voltages at TP's 1 to 5, and TP8 ?

TP1(0.05vac)
TP2(1.25vac)
TP3(0.09vac)
TP4(0.08vac)
TP5(0.05vac)
TP8(0.36vac)

[g1]

Unfortunately, on closer look, the AC voltages shown on schematic are not trustworthy. They can't put 170mV at the input jack and have 700mV at TP1, maybe TP1 should have been pin1 of U1.
Your voltages do pretty much follow the pattern, being generally around 20% of listed after TP3.

Raise you input signal level til you have 0.1VAC at TP5. Measure AC volts at both sides of C11, both sides of R25, and TP12.

[ca7922303]

Unfortunately, on closer look, the AC voltages shown on schematic are not trustworthy. They can't put 170mV at the input jack and have 700mV at TP1, maybe TP1 should have been pin1 of U1.
Your voltages do pretty much follow the pattern, being generally around 20% of listed after TP3.

Raise you input signal level til you have 0.1VAC at TP5. Measure AC volts at both sides of C11, both sides of R25, and TP12.

Signal@0.34v sine
(0.1vac)@TP5
R25(0.1/0.0vac)
TP12(0.27vac)
C11(0.1/0.1vac)