I need electrical help.

[Dputiger]

I posted about this about a week ago but I'm going to lay the problem out with some new information.

About a week ago my LCD began making a strange, high-pitched buzzing sound when hooked to my computer. (I use a Pioneer SX-3600 receiver with two Advent Loudspeakers). Disconnecting the LCD instantly stopped the noise, as did unplugging it. Moving the LCD to an entirely different computer (but using the same sound system) reproduced it.

So, the explanation for all this behavior I've been given thus far is that there is a short in the LCD that is grounding out through the DVI cable. Ok, fine. I decided I'd attach a ground from the receiver to the case just to see if that'd help (my receiver has a nub marked GND for a ground attachment.

So I did that. And here's the whacky part.

If I attach a ground from receiver to case the sound dies significantly but will be produced even with the volume on the receiver turned to 0.

Now here's where I just get lost entirely. If I attach one end of the wire to ground and one end back to the either the left or right channel cables headed back to the computer where the LCD is attached the sound almost completely vanishes.

I'm just plain lost and to make matters worse Hitachi is telling me they really don't know what's wrong. I'm not entirely sure the problem isn't in my stereo so if ANYONE out there can help I'd appreciate it.

[Ruler2112]

Could you clairify the second to the last paragraph? You hook a cable from the ground on your receiver to the cables carrying the sound?

It's your LCD making the noise, not your stereo, correct?

[MDS]

sounds like feedback due to poor sheilding of the audio cables. Have you tried a reg set of computer speakers to see if you still get the noise? I know that if I plug my patch cord for my audio and s-video for video into my 42" TV into one set of inputs and my set top DVD into another set of inputs the computer audio would make the tv speakers hummmmm. But when I unplug the DVD player sound goes away or If I unplug computer from it. So they just interfeer each other.

[Dputiger]

My stereo makes the noise ONLY when the LCD is hooked up to the same machine (or one of the machines, since I can run multiple computers to the receiver) that the receiver is hooked in to.

Also I've been using this combo in pretty much this exact way for the last year and the buzzing only started last week. I'd be surprised if it was a shielding issue, and in any event, the speakers sit a good 3-4 feet away from the LCD.

[MDS]

Does the LCD have an internal power supply or an external power supply pack? I wonder if the transformer could be going bad but don't really know. I have my main box going through my Onkio home theater system and run dual monitors one being an 17" NEC LCD without any problems for quite some time now.