CurtPalme.com Home Theater Forum

[unkyjoesa]

Greetings all,

I just recently got a component cable for my Xbox and when I plug it in to the back of the Xbox I get a humming from my amp.

I have replaced the cables to the amp, tried plugging the xbox into another circuit you name it I cant seem to get rid of the buzzing, I guess I could invest in one of those cheap GL Isolaters but before spending the money I wanted some advice.

THanks in advance.

[macgyver655]

Are the A/C plugs on the amp and Xbox 2 or 3 prong?

[lyd]

[unkyjoesa]

MacGyver:

Xbox is the two prong plug with the Microsoft plug, I think it was issued to correct power problems with the Xbox, it has the little reset buttons on it and a green light.

The Amp is a two prong plug.

The Projector and Xbox are plugged into the same PS.

The AMP is in the equip closet and plugged into a very large TrippLite battery backup unit.

What is odd, I can unplug the Xbox from the PS and the buzz is less but still there. Only when I unplug the connector cable from the back of the Xbox does the buzz disappear. The projector doesn't even need to be plugged in and I still get the buzz.

Weired.

[macgyver655]

Sounds more like a feedback issue then a ground loop issue. Did you try the amp plugged into an outlet without the battery backup? Also when you say, I can unplug the Xbox from the PS and the buzz is less but still there, do you mean you unplug the A/C from the outlet or the power supply cable from the Xbox? Last when you say, I unplug the connector cable from the back of the Xbox does the buzz disappear, do you mean the cable from the power supply or the cable to the amp?

[lyd]

How is your sat box connected into all of this, and what happens when you disconnect it?

For that matter, other than the projector, are there any other devices that have a ground to earth connected to anything?

lyd

[Tom.W]

Read this.

http://www.epanorama.net/documents/groundloop/index.html

[voodoo7869]

just feed the amp optical and no feed back at all.
have you tried a different componant cable?
xbox 360 has a floating ground setup so feedback is possiable to standard ground systems.

[macgyver655]

[unkyjoesa]

I have an Xbox, not a 360.

I have tried two different component cables for the Xbox from 2 different manufacturers, the SAT receiver is plugged into a different amp than this one is.

Like I said, when I pull the component cable from the back of the Xbox the buzz goes away. Whether the Xbox is plugged into the power or not, this is what is so weird, perhaps there is a bad solder joint on the Xbox plug itself internally.

I dont think it is a ground loop issue as much as it perhaps might be a connector problem with the Xbox itself.

What do you all think? Tear open the Xbox and check the connector?

Thanks for the help.

[macgyver655]

Have you tried with just the audio wires connected and the component wires not connected?


Is this your cable?

[unkyjoesa]

Ok, I'm stupid, I had the plug in upside down.

Polarity does matter, and the Xbox plud does not have different sized plugs they are the same so I had the neutral and the hot reversed, I turned the plug around and whala no buzz!

Macgyver, I have the $20 component cable with the thicker high quality wire. I had that cable initially and it was a nightmare, the picture was horrible, like using zip cable instead of a higher quality cable.

Thanks to all of you for your help, and why the hell arent those spades a different size to prevent morons like myself from flipping them around?

[voodoo7869]

that makes zero sense at all. By definition ac current flows bolth ways. so flipping the power cable around makes no difference. you probably have a faulty connection in the xbox. check the solder points on the input plug. The only way this could possiably have an effect is that you have an out of balance neutral in the outlet you are using.
What i mean by that is you have to high of an amperage difference between the neutral and the ground at the main panel.
the difference should be no more than 5 amps and that is pushing it for best noise rejection. it is a really comon problem because in construction they often use one neutral for 2 to 3 hots. I had several circuts that were out of balance. and it does create noise.

[unkyjoesa]

VooDoo; It's back.

Time to take apart the Xbox and fix the connector, I took the unit out of the environment it was in and moved it to another TV and amp and had the same problem.

I am going to clean the connectors first, manufacturers are so fond of these gold plated connectors without realizing that the connectors on the unit are a different type of metal, and what do dis-similar metals do to one another? The corrode or oxidize.

I will let you all know what I found.

[voodoo7869]

please do that would be great