Audio Systems: Display noisy on all speakers output, rear projection tv, rf noise

Question
After replacing 2 STK modules I end up with a hissing noise. Found out it's the display when plugged in the board. 3 wires are going to the display: 2 are for AC to the (FL) direct from the power transformer and 1 goes to "Volt Protection" (VP). Any ideas? . When unplugged (the fluo display) the amplifier works great...volume and all but we don't see a thing. Thanks so much.


Answer
What is the product?  STKs are used in the convergence circuit of a Japanese rear projection tv.  But, I don't know what display you are talking about and I need to know what speakers you are referring to?   External speakers powered by receiver?

You might just have a bad display that has gone gassy and is producing the hissing noise which is an rf noise getting back into the audio section and being rectified by one of the audio amp sections.  Sometimes you can swamp out the rfi by adding a small capacitor to the VP lead.  Maybe something a small as 100 pf to ground.  Try something like that.

But, if that doesn't work, give me more details of the setup and equipment so I know what you've got.
C