My SW8 has recently developed an audio issue. It plays for a few seconds to
a minute or so, then the audio just suddenly dies. I can still get audio out
the line out jack, but nothing from the speaker or headphones. I strongly
suspect the LA4555 output IC, but I would love to be able to do some signal
tracing to make sure the problem doesn't lie further up the audio chain.
Does anyone have, or know where I can find, a schematic or service manual
for the SW8?

On 12/11/11 06:05 , Brenda Ann wrote:
My SW8 has recently developed an audio issue. It plays for a few seconds
to a minute or so, then the audio just suddenly dies. I can still get
audio out the line out jack, but nothing from the speaker or headphones.
I strongly suspect the LA4555 output IC, but I would love to be able to
do some signal tracing to make sure the problem doesn't lie further up
the audio chain. Does anyone have, or know where I can find, a schematic
or service manual for the SW8?

I got mine from RL Drake. But that was years ago.

BAMA has an archive of manuals and schematics, though. Check them out.

On Sun, 11 Dec 2011 10:43:39 -0600, D. Peter Maus wrote:

On 12/11/11 06:05 , Brenda Ann wrote:
My SW8 has recently developed an audio issue. It plays for a few
seconds to a minute or so, then the audio just suddenly dies. I can
still get audio out the line out jack, but nothing from the speaker or
headphones. I strongly suspect the LA4555 output IC, but I would love
to be able to do some signal tracing to make sure the problem doesn't
lie further up the audio chain. Does anyone have, or know where I can
find, a schematic or service manual for the SW8?

I got mine from RL Drake. But that was years ago.

BAMA has an archive of manuals and schematics, though. Check them
out.

You can find the pinouts of the active devices and look for gain IN v
OUT. Do you have a scope? A Hi-Z input amplified speaker?

On 12/11/2011 7:05 AM, Brenda Ann wrote:
My SW8 has recently developed an audio issue. It plays for a few seconds
to a minute or so, then the audio just suddenly dies. I can still get
audio out the line out jack, but nothing from the speaker or headphones.
I strongly suspect the LA4555 output IC, but I would love to be able to
do some signal tracing to make sure the problem doesn't lie further up
the audio chain. Does anyone have, or know where I can find, a schematic
or service manual for the SW8?

Yes, BAMA has it (for free) at this URL:

bama.edebris.com

Choose "drake" and then "SW8"

Good luck and let us know what you find.

"Joe from Kokomo" wrote in message ...

On 12/11/2011 7:05 AM, Brenda Ann wrote:
My SW8 has recently developed an audio issue. It plays for a few seconds
to a minute or so, then the audio just suddenly dies. I can still get
audio out the line out jack, but nothing from the speaker or headphones.
I strongly suspect the LA4555 output IC, but I would love to be able to
do some signal tracing to make sure the problem doesn't lie further up
the audio chain. Does anyone have, or know where I can find, a schematic
or service manual for the SW8?

Yes, BAMA has it (for free) at this URL:

bama.edebris.com

Choose "drake" and then "SW8"

Good luck and let us know what you find.


--------------------------------------------------------------------------------
--------------------------------------------------------------------------------

Alas, BAMA has only the user manual, which I already found, and does not
have a schematic.

On 12/11/2011 3:33 PM, Brenda Ann wrote:
[...]

Alas, BAMA has only the user manual, which I already found, and does
not have a schematic.

I've looked all over the usual sources on the Web, and have so far
come up with nothing. It's as if someone has scoured all traces of
that schematic. Perhaps you can find a sympathetic ear at Drake.

Best of luck,


Kevin.
--
http://nationalvanguard.org/
http://kevinalfredstrom.com/

On Dec 11, 7:05*am, "Brenda Ann"
wrote:
My SW8 has recently developed an audio issue. It plays for a few seconds to
a minute or so, then the audio just suddenly dies. I can still get audio out
the line out jack, but nothing from the speaker or headphones. I strongly
suspect the LA4555 output IC, but I would love to be able to do some signal
tracing to make sure the problem doesn't lie further up the audio chain.
Does anyone have, or know where I can find, a schematic or service manual
for the SW8?

www.dproducts.be . But, they seem to have just the user manual . Big
disappointment.

On 12/11/11 06:05 , Brenda Ann wrote:
My SW8 has recently developed an audio issue. It plays for a few
seconds to a minute or so, then the audio just suddenly dies. I can
still get audio out the line out jack, but nothing from the speaker
or headphones. I strongly suspect the LA4555 output IC, but I would
love to be able to do some signal tracing to make sure the problem
doesn't lie further up the audio chain. Does anyone have, or know
where I can find, a schematic or service manual for the SW8?


It occurs to me, if you know the pinout on the suspect IC, you can
trace out the path back to the detectors, or at least the preamp,
and do your diagnostics, anyway.

A long way to go, but at least a start.