Failure modes in sound cards

[Randy Day]

I've had a couple older pc's that I used for music servers.
They were both hooked up to an 80's-vintage Onkyo amp.

In both cases, the onboard sound cards worked for a long
time, but then just stopped working. The pc's still work,
just not the sound function.

Since I'm getting tired of configuring new old pc's for
the task, I'm wondering if there's a common failure
issue I can look for.

Any suggestions?

 

Ya gotta get this narrowed down to software or hardware. If these ar older PC/soundcards, they might be the kind with an actual power output on them. I had a fw of these, it was pretty cool to be able to just hook the speakers up directly without having to pulg them in.

Not that the sound was all that great, but you could hear it.

If your OS reads that the device is working properly and it indeed has a power output (typically about 2 watts per channel off the 12 volt line) it is very possible that the output INC, likely a "TDA" series chip, is wiped out.

Now, IF this is the case and you have fried moe than one, you need to look at the load. You could be overloading it, or hav a shorted cable or whatever. One failure just happpens, two do not.

Shit like this is why I do not do software or driver updates. IT WORKS NOW, why in living God's fucking hell would I fuck with it ? You think I'm crazy ?

Don't bother answering that.
Don't bother answering that.

Anyway, ohmmeter checks might see the IC shorted and an open small resistor or fusible. Actually a foil on the board could be a fusd, in which case you would have to simply find the circuit point it goes to and apply a jumper..

Anyway, out o fcuriousity, what the hel kind of PC is this ? How old and all that.

 

Oh ! This is impportant...

Some amps/preamps had the input switch st up so it shorted out the inputs that were not selected. If that sound card has a power output, the Onkyo could blow it if it shorts the unselected inputs. Quite a few older vintage type audio stuff does this.

 

[Randy Day]

In article <444588a8-3796-40bd-bd8d-5b5875c3dffc@googlegroups.com>,
jurb6006@gmail.com says...

[snip]

Anyway, out o fcuriousity, what the hel
kind of PC is this ? How old and all that.

Just a couple of boat-anchor win98 boxes.
Load them up with Winamp, a bunch of mp3s
and internet radio links, and voila -
music to get you through the day.

And, in case I gave the wrong impression,
they didn't get hooked up and blow
immediately; they both worked for months
on end, and then ... didn't.

So either lightning got them, or there's
a mismatch that's slowly cooking something
inside. I guess my question boils down to:
Do soundcard outputs have a blocking
capacitor? the schematic of the Onkyo
has them on the inputs, but if they're
leaky, that's a problem.

As a general rule, are soundcard outputs
dc-blocked, or direct-drive?

 

[Michael A. Terrell]

Randy Day wrote:

In article <444588a8-3796-40bd-bd8d-5b5875c3dffc@googlegroups.com>,
jurb6006@gmail.com says...

[snip]

Anyway, out o fcuriousity, what the hel
kind of PC is this ? How old and all that.

Just a couple of boat-anchor win98 boxes.
Load them up with Winamp, a bunch of mp3s
and internet radio links, and voila -
music to get you through the day.

And, in case I gave the wrong impression,
they didn't get hooked up and blow
immediately; they both worked for months
on end, and then ... didn't.

So either lightning got them, or there's
a mismatch that's slowly cooking something
inside. I guess my question boils down to:
Do soundcard outputs have a blocking
capacitor? the schematic of the Onkyo
has them on the inputs, but if they're
leaky, that's a problem.

As a general rule, are soundcard outputs
dc-blocked, or direct-drive?

There are coupling capacitors on the inputs and outputs. Are these
computers online, or dedicate with no outside connections?



--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.

 

[Randy Day]

In article <U6KdnSZdkrLZdUrOnZ2dnUVZ_g2dnZ2d@earthlink.com>,
mike.terrell@earthlink.net says...

[snip]

As a general rule, are soundcard outputs
dc-blocked, or direct-drive?

There are coupling capacitors on the inputs and outputs. Are these
computers online, or dedicate with no outside connections?

Online, for internet radio.

 

[Mark Zacharias]

"Randy Day" <randy.day@sasktel.netx> wrote in message
news:MPG.2e40d150de0a2e1c9896a4@aioe.org...

I've had a couple older pc's that I used for music servers.
They were both hooked up to an 80's-vintage Onkyo amp.

In both cases, the onboard sound cards worked for a long
time, but then just stopped working. The pc's still work,
just not the sound function.

Since I'm getting tired of configuring new old pc's for
the task, I'm wondering if there's a common failure
issue I can look for.

Any suggestions?

Are you sure the receiver is not at fault? Onkyo's aren't the most reliable
things, now or back then either.

I'm assuming you are using an analog output from the sound card - do the
other analog inputs work OK? Regular stereo or using surround sound fields?


Mark Z.

 

[Michael A. Terrell]

Randy Day wrote:

In article <U6KdnSZdkrLZdUrOnZ2dnUVZ_g2dnZ2d@earthlink.com>,
mike.terrell@earthlink.net says...

[snip]

As a general rule, are soundcard outputs
dc-blocked, or direct-drive?

There are coupling capacitors on the inputs and outputs. Are these
computers online, or dedicate with no outside connections?

Online, for internet radio.

Does it have antivirus, a firewall and malware protection?



--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.

 

[Randy Day]

In article <P6adnVWakMCgFUXOnZ2dnUVZ_owAAAAA@earthlink.com>,
mike.terrell@earthlink.net says...

[snip]

> Does it have antivirus, a firewall and malware protection?

I hadn't considered malware, but I suppose
it's possible. Is there malware that turns
off the sound card?

 

[Michael A. Terrell]

Randy Day wrote:

In article <P6adnVWakMCgFUXOnZ2dnUVZ_owAAAAA@earthlink.com>,
mike.terrell@earthlink.net says...

[snip]

Does it have antivirus, a firewall and malware protection?

I hadn't considered malware, but I suppose
it's possible. Is there malware that turns
off the sound card?

It can mess up almost anything. The sound may not work, simply
because the malware is using too many resources.


--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.

 

[Jeroni Paul]

Most audio and TV devices are not grounded so a dangerous voltage develops in their grounds. Now consider what happens if the ground in your audio cable fails open, a dangerous voltage will be applied.to the audio inputs. It is common for audio jacks to make unreliable contacts, so this could be the cause of your problem. To.stop this I would wire a reliable connection between PC and amplifier grounds.

 

[Mark Zacharias]

"Jeroni Paul" <JERONI.PAUL@terra.es> wrote in message
news:1900e4a7-8fb1-4545-8714-4c863cd27700@googlegroups.com...
*Most audio and TV devices are not grounded so a dangerous voltage develops
in their *grounds. Now consider what happens if the ground in your audio
cable fails open, a *dangerous voltage will be applied.to the audio inputs.
It is common for audio jacks to make *unreliable contacts, so this could be
the cause of your problem. To.stop this I would wire a *reliable connection
between PC and amplifier grounds.

Horseshit. It would make a loud hum noise - nothing worse.

I see this sort of thing all the time.

Mark Z.

 

[Mark Zacharias]

"Michael A. Terrell" <mike.terrell@earthlink.net> wrote in message
news:nvSdnY0VaP07sUTOnZ2dnUVZ_tWdnZ2d@earthlink.com...

Randy Day wrote:

In article <P6adnVWakMCgFUXOnZ2dnUVZ_owAAAAA@earthlink.com>,
mike.terrell@earthlink.net says...

[snip]

Does it have antivirus, a firewall and malware protection?

I hadn't considered malware, but I suppose
it's possible. Is there malware that turns
off the sound card?


It can mess up almost anything. The sound may not work, simply
because the malware is using too many resources.


--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.

If it's an older machine - maybe the bios battery failed or otherwise the
audio options maybe got reset in the bios?

Turned off your sound card in favor of an on-board device? Or vice-versa?
Turned OFF an on-board device if that's what the OP was using?

Has OP checked sound and audio devices under Device Manager? Driver good?


Mark Z.

 

On Thursday, July 31, 2014 1:26:31 AM UTC-7, Mark Zacharias wrote:

Horseshit. It would make a loud hum noise - nothing worse.
I see this sort of thing all the time.

Mark Z.

Normally I would agree with this - until it happened to me. It DID make a loud hum and then the sound died - permanently. FWIW it was a Realtek onboard sound chip. Device manager said it was operating correctly. Yeah, the DIGITAL parts worked but the analog was toast.

G˛

 

[Randy Day]

In article <53d9fe80$0$27182$4c5efc6d@fastusenet.org>,
mark_zacharias@labolgcbs.net says...

[snip]

If it's an older machine - maybe the bios battery failed or otherwise the
audio options maybe got reset in the bios?

Turned off your sound card in favor of an on-board device? Or vice-versa?
Turned OFF an on-board device if that's what the OP was using?

Has OP checked sound and audio devices under Device Manager? Driver
good?

Another set of excellent possibillities.
I will definitely check them out.

This group rocks!!!

 

[Jeroni Paul]

Mark Zacharias wrote:

Horseshit. It would make a loud hum noise - nothing worse.
I see this sort of thing all the time.

Wrong, this is very risky to do and I have seen lots of stuff damaged that way. Common to damage the inputs on TV scart sockets, TV outputs in video cards, audio inputs and outputs, etc.

I particularly hate RCA connectors, most of them have the center terminal longer than the ground so it is the first to contact when plugged. Very dangerous situation if there is no other link joining the grounds of both devices. Audio jacks and F plugs suffer the same problem. Other connectors are somewhat better where ground usually contacts first like USB, DVI, legacy PC ports (serial, parallel, VGA) and Scart. But do not rely on that, connector design if far from perfect in this regard.

To avoid nasty surprises I always plug sensitive cables with both devices unplugged from mains and have the precaution to momentarily touch grounds first to discarge any static.

 

[Mark Zacharias]

"Jeroni Paul" <JERONI.PAUL@terra.es> wrote in message
news:9164fb16-b71e-43c0-b54c-4072b6d4b8c2@googlegroups.com...
Mark Zacharias wrote:

Horseshit. It would make a loud hum noise - nothing worse.
I see this sort of thing all the time.

Wrong, this is very risky to do and I have seen lots of stuff damaged that
way. Common to >damage the inputs on TV scart sockets, TV outputs in video
cards, audio inputs and outputs, >etc.

I particularly hate RCA connectors, most of them have the center terminal
longer than the >ground so it is the first to contact when plugged. Very
dangerous situation if there is no other >link joining the grounds of both
devices. Audio jacks and F plugs suffer the same problem. >Other connectors
are somewhat better where ground usually contacts first like USB, DVI,
legacy PC ports (serial, parallel, VGA) and Scart. But do not rely on
that, connector design if >far from perfect in this regard.

To avoid nasty surprises I always plug sensitive cables with both devices
unplugged from >mains and have the precaution to momentarily touch grounds
first to discarge any static.

I'm with you on not plugging stuff in when powered. It's only common sense.

I stand by my statements however. Been repairing audio for more than 30
years, and have factory training from majors such as Sony, Yamaha, Pioneer,
NEC, Hitachi, Denon-Marantz, and others.

It's even OK to lift the chassis ground from a desktop computer box to
eliminate a ground loop. Unless the unit's power supply primary short happen
to short to chassis, there is no shock hazard. That is why the primary
circuit is isolated.

We have these types of discussions on the groups all the time. One recent
one had to do with the third wire ground on oscilloscopes. Yes, you should
leave them intact and not defeat them, but no harm will arise from
bypassing - they are there more for manufacturers liability issues, where
possibly hundreds of thousands or even millions of these things are going to
be in use in all kinds of situations the manufacturer cannot control, often
by people with uncertain levels of training or experience.


Mark Z.

 

[Jeroni Paul]

While ground loop noise is fixed disconnecting grounds *one* ground *must* remain connected so both chassis are at the same potential. In this case both devices are properly grounded and no loud hum occurs.

But if one or both devices are not properly grounded and you do not connect audio ground you will get a loud hum and you are asking for trouble. The ungrounded device is being grounded through audio circuits. This is not OK and may result in damage and you was not right when you said that was safe to do.

Of course the danger level depends on the equipment used. Some people likes to connect the PC to a music box that in turn is connected to a FM aerial together with some TV sets and other equipment all of them ungrounded. In this scenario many devices are grounded through the audio cable, a real danger if it goes open or it is plugged/unplugged.

 

>"Denon-Marantz"

Denon-Marantz ? I thought Sony bought Marantz.

???

 

One thing to consider is that PCs are usually equipped with three prong cords which means they have an Earth ground. this means that all the line leakage of any connected equipment flows throught the commons, or grounds on anything like an audio cable, anything.

I had to deal with a wierd ground loop problem on a commercial projector because it was properly grounded and so was thre cable coming in. Turns out the guy had two ground rods installed and there apparently was a ground gradient. the guy is an electrician actually ! I had to build him an isolator. It came out of an old TV that had a hot chassis, all I had to do was attach the correct connector.

That happened because the projector was three prong, but can happen to anything else like that, if they do not go to the same ground.

In other words, your ground is not my ground.