"Dave" wrote in message
news:G007i.60698$g63.51228@edtnps82...

"Peale" wrote in message
. 196...
wrote in
ups.com:

On 29 May, 15:43, Peale wrote:

While dumpster diving I found a 2.1 speaker set. Static in the left
speaker.

I swapped speakers, problem persisted.

in which speaker?

LOL...in the left speaker. If the problem traveled, I'd have found my
problem. ;-)

Just short the audio out at the various points in the signal chain
(dont short power amp output tho). When shorting before a stage made
no difference & shorting after it killed crackling, you know where its
coming from. Prodding with a bit of plastic also helps locate if its a
dry joint.

I touched up every joint I could, esp. the connectors on the PCB.

What do you mean, short the points? Take a wire and jump the signal
closer along in the chain to the output?

No, jump the signal to ground. You're effectively killing the audio
signal input from that point on. If the crackling persists, that means
it's being introduced downstream of the point you've shorted. Just keep
moving downstream along the signal path until the crackling goes away.
The component just upstream of your jumper point is the likely culprit.

That is the preferred way of pinning down a problem like this, and is often
more effective than using a 'scope to try to distinguish between the crackly
noise, and the inherent stage noise. I would, however, warn agains employing
a direct shorting wire to do the job, unless you have schematics for an amp
to know exactly the 'safe' points to apply a direct ground connection to.
There are places that you certainly don't want to short directly to ground,
if you want the components to keep their magic smoke locked in. I would
recommend that you use a 47uF 35v capacitor, negative leg to ground, as your
'shorting wire'. The actual value isn't critical - whatever comes to hand.

Arfa