Ampeg BA115HP Output and crackling/static

[ca7922303]

Check value of R66 and check diode D12 with diode test.

R66(304 ohms)
D12(0.0 v) diode test

[x-pro]

D12(0.0 v) diode test

how do you measure and what?
Take any zener and compare its measurement reading to yours

[g1]

Disconnect one end of D12 and re-check.

[x-pro]

Disconnect one end of D12 and re-check.

Don't do that. It's dangerous. It'll burn the chips, If you apply power to the amplifier

[g1]

Don't do that. It's dangerous. It'll burn the chips, If you apply power to the amplifier

You don't apply power to the amplifier doing diode checks.

[g1]

I should have been more clear, when I mentioned 'using diode test' I meant the diode check function on a multi-meter.

[ca7922303]

how do you measure and what?
Take any zener and compare its measurement reading to yours

Black lead to ground end of diode
Red Lead to other end
Diode test function DMM
D11(.409 v) diode test

[x-pro]

it's fine.
is there any difference when checking D12 ?

[ca7922303]

Disconnect one end of D12 and re-check.

D12(0.58 v) diode test((+) leg lifted)

[x-pro]

You can put it back in place.
Now check C40 for short circuits.

[ca7922303]

You can put it back in place.
Now check C40 for short circuits.

C40(0.6 ohms)

[g1]

C40(0.6 ohms)

Removed or with one leg disconnected?

[ca7922303]

Removed or with one leg disconnected?

In circuit

[ca7922303]

Removed or with one leg disconnected?

C40(OL)removed

[x-pro]

And what is the voltage now on D12 (set in place) when power is applied to the amp?