I have a hitachi 53SDX89B model rear projection. I was recently trying to have it connected to ATT Uverse TV. Every time the tech hooked the DVR receiver to one of the inputs, it knocked out the service. We tried two different receivers, but it was the same on both. The problem occurred a few seconds after the TV is turned in, no matter which input is used. The Tech said there was power back feeding out of the inputs. Can this board be replaced and what is the PN? Does any of this make sense?

All inputs of the tv's are zero voltage I think the problem must be on the DVR reciever because you already try two units and same thing happens.the tech must see the compatibility of the TV and the reciever there must be a problem in there...

Hi,
Hitachi 53SDX89B is September 1999 model as its mentioned on its service manual that I have.
Since tv is too old so I'm afraid, no spare boards or parts would be available any more to fix its AC leaky current issue that damaging ATT U-verse service. (power back feeding out, we call it AC leakage).
There is one solution for that problem, buy Isolation Transformer and plug your tv in it, that will cure AC leakage from your tv and wont hurt any thing attached/ connected with this tv. Your tv consume 245 Watt power while working so 500 Watt isolation transformer would be good enough to keep turn On tv for hours/ days.
Below is an image of basic isolation transformer and click HERE to get required 500W isolation transformer.
Hope these info will help you.
Thanks.