Computer Hope

Hardware => Hardware => Topic started by: rjbinney on October 05, 2006, 11:36:04 AM

Title: Weird interference on headphone output
Post by: rjbinney on October 05, 2006, 11:36:04 AM
Hey all -

I watch DVD's and downloaded TV through my laptop on my television. I use the S-Video output, and have a Y-connecter that plugs into my headphone jack and splits into two RCA audio plugs. Has worked like a charm for quite a while.

Had to reformat my HD, and now when I plug in, I get a weird buzzing sound through the television's speakers. It doesn't happen on headphones, just through the TV's speakers. The sound (dialog, music) still outputs fine, it's just got this extra layer of buzzzz.

Here's the kicker - when the machine is running on its battery, it's fine. It's only an issue when running off of AC. And, yes, I have used THIS machine with THESE cables through THIS power outlet and not had this problem. The ONLY delta is the reformatting of my HD.

I've updated all drivers off the Dell website... So I don't know what it could be. Thoughts?


Thanks!

rjb
=====

Dell Inspiron 6000
XP SP2
Title: Re: Weird interference on headphone output
Post by: ale52 on October 05, 2006, 11:48:13 AM
"...I have used THIS machine with THESE cables through THIS power outlet and not had this problem."

Gotcha  ;)

Just for grins  ;D have you tried another outlet?

Alan <><  :D
Title: Re: Weird interference on headphone output
Post by: rjbinney on October 05, 2006, 11:54:23 AM
Yes.

It's the same circuit, however... (Short of running a 50' extension cord, it would have to be the same circuit).

Sorry - tried to head off all the "Did you try soapy water?" questions....
Title: Re: Weird interference on headphone output
Post by: Raptor on October 05, 2006, 12:07:26 PM
Quote
Yes.

It's the same circuit, however... (Short of running a 50' extension cord, it would have to be the same circuit).

Sorry - tried to head off all the "Did you try soapy water?" questions....

Did you try getting drivers from the soundcard manufacturer's website instead of the ones Dell supplied you with?
Title: Re: Weird interference on headphone output
Post by: rjbinney on October 05, 2006, 12:14:43 PM
No, I didn't.  

In Device Manager=>Sound, video, and game controllers, I have the following options:What to do from there???

Thanks!
Title: Re: Weird interference on headphone output
Post by: Raptor on October 05, 2006, 12:17:16 PM
Nevermind,

Quote
Audio Codecs and Integrated Audio Support

    * SigmaTel is not a sound card manufacturer, we design and produce integrated circuits directly for manufacturers.
    * Unfortunately, due to licensing restrictions, we are unable to provide drivers to end-user's.
    * All end-user technical support, including drivers, should be directed to the product manufacturer.

Have you tried using a previous version of your soundcard driver?
Title: Re: Weird interference on headphone output
Post by: rjbinney on October 05, 2006, 12:39:57 PM
I somehow don't have the original Dell Drivers CD that came with my machine... So I had to DL off of Dell's website. Is there a place where stuff like that could be archived?
Title: Re: Weird interference on headphone output
Post by: rjbinney on October 05, 2006, 01:04:39 PM
I ran Everest and got the following:

Multimedia-> Windows Audio->
midi-out.0    0001 0066        Microsoft GS Wavetable SW Synth
mixer.0       0001 0068        SigmaTel C-Major Audio
wave-in.0     0001 0065        SigmaTel C-Major Audio
wave-out.0    0001 0064        SigmaTel C-Major Audio

and

Multimedia> PCI/PnP Audio-> Intel 8280 1FBM ICH6-M AC'97 Audio Controller [B-1]                                              PCI

Doe that help anything?
Title: Re: Weird interference on headphone output
Post by: Raptor on October 05, 2006, 04:01:13 PM
No, not really.

I'm no expert on sound, I'd try to find out if Dell knows about this problem and if they have a solution. Or perhaps try contacting Sigmatel as well.

Rolling back the drivers, if you can find them, I don't know if Dell archives them, is one plan. The other is going over all your sound and audio device settings in the control panel to make sure it's not set too loud which could cause interference.
Title: Re: Weird interference on headphone output
Post by: rjbinney on October 05, 2006, 04:04:59 PM
Quote
The other is going over all your sound and audio device settings in the control panel to make sure it's not set too loud which could cause interference.
Wouldn't explain the contrast between battery power and AC power.

But thanks for suggesting I try to get help from Dell - I just spit coffee all over my keyboard.
Title: Re: Weird interference on headphone output
Post by: Raptor on October 05, 2006, 04:09:07 PM
Maybe it has to do with power saving. Try working with different power saving schemes.
Title: Re: Weird interference on headphone output
Post by: rjbinney on October 05, 2006, 04:53:29 PM
Brilliant suggestion - but made no difference.

I also discovered that it is independent of the computer's volume. Regardless of what the volume is, as soon as you plug it into the jack you get the buzz.
Title: Re: Weird interference on headphone output
Post by: rjbinney on October 05, 2006, 05:53:16 PM
OK, here's the deal. When the coax from the wall to the cable box is disconnected, the buzzing goes away.

So the buzzing is present when the computer is plugged in AND cable is connected.

If I disconnect from either the wall or the cable box, it goes away.

If I put the computer on battery power, it goes away.

Very strange.
Title: Re: Weird interference on headphone output
Post by: GX1_Man on October 05, 2006, 06:59:23 PM
All drivers for any Dell ever made are on their website. These are even preferable to a driver CD from Dell, because they are likely updated.

If you think this is a Dell problem, post in the appropriate Dell support forum.

It sounds like an electrical interference/line noise problem however, based on the info given.

May Fed or Homer, our resident electricians, can help out.  ;)
Title: Re: Weird interference on headphone output
Post by: rjbinney on January 01, 2007, 02:27:07 PM
Bump.
Title: Re: Weird interference on headphone output
Post by: WillyW on January 01, 2007, 03:51:13 PM
Quote

- - -
Here's the kicker - when the machine is running on its battery, it's fine. It's only an issue when running off of AC.
 - - -


To me, it sure sounds like a power supply problem.   When there is no load on the power supply, the power supply does not generate the interferance.   Put a load on it, and it does.
I've never looked into one, but the supply is likely to be some sort of switching power supply, and they are inherently noisy.

Why yours would suddenly become unable to filter out the noise at the same time as your reformat - I have no idea.   I can't see how they are related.
Wild coincedence maybe?

Check out:  http://computer.howstuffworks.com/question352.htm

But if I recall correctly,  those beads mentioned do their best work as the frequency goes higher and higher.    I suspect that if your noise is related to the  power supply, it would be low frequency.... unless it is a harmonic.