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Noise through TV, new TV/Cable Box?

post #1 of 3
Thread Starter 
Hey there guys, been searching for a week or so on here with no real answers yet. I'll try my best to explain the problem and see what happens.

We just got a new fancy 55" Plasma Panasonic TV (their VT25 series) and also got digital cable (HD box) from Cox Cable here in Santa Barbara, CA. When hooking everything up there's a sounds that emits from the cable line that each channel the sound can get louder or softer depending on what picture is showing. It's hooked up via a HDMI cable to the TV (so the TV has no coax going to it).

The cable goes into the house, then splits off to other rooms but the cable coming in comes strait from the splitter to the TV. It's the most direct path that it can come. They are all 5-2300ghz splitters that I picked up from home depot last week. My picture quality is clear, no problems or issues there, it just that there is a loud hummm or background noise on every channel only when the coax is on. When my Xbox360 s on I hear no hum or anything (other than the normal TV sound).

I went as far as grounding the splitters to the cable box but it didn't help any. I'm tempted to try another coax cable from the splitter to the TV and see if that changes anything (might be the cable) but if not the only thing I can come up with is a ground loop issue. We have 2 other TV's in the house (both LCD TV's) and neither of them make any noise or hum on any channel. Our TV will do it while on MUTE as well so I know it's coming in this TV with the line.

Short of calling Cox for a service call does anyone have any ideas on what might be causing this? It's driving me nuts LOL. This is my first nice TV set + I have surround sound coming next week and just would like it all dialed with no un-necessary sound/video issues.
post #2 of 3
Most consumer AV gear uses two wire rather then grounded plugs, try reversing the plugs TV and Cable box.

If you disconnect the coax from the cable box and have the TV display locally generated image from the cable box is the noise still there?

Are you close enough to transmitter to try over the air reception? This will identify if problem is the TV itself or some sort of grounding problem.
post #3 of 3
Reversing the plugs is worth a try, but probably can't be done since most all plugs are polarized.

You could try to identify/isolate by trying a few things.
1) disconnect HDMI cable from TV. Run coax straight from wall to TV.
2) replace HDMI with component cable and audio cables.
3) try another cable box (if one is available)
4) and... just for kicks, unplug the TV and cable box from wall power for a few minutes. Sometimes a hard power cycle works wonders.
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