So here's the situation. We have bad cable reception on a tv in our house, and we have 3 other tvs that are fine. The main cable line comes into the house with no electricity on it. It splits in our utility room to all the other tvs in the house. Now don't necessarily get this next fact fixed in your mind - but the tv with the electrical problem is in the OLD secton of our remodeled house, and the GOOD tvs are in the new section. So, we have old knob-and-tube ungrounded recepticles in the old section, where the problem tv is. So, of course, our first guess was that our tv, cable box, and tivo were all just grounding via the coax because the poor little things had no ground in the super-old recepticles. HOWEVER - we did a little test and ran an extension cord from the new kitchen (with romex grounded GFI's) to the missbehaving entertainment boxes and STILL had: 3 volts from the TV, 20 volts from the large cable box, and 20 volts from the TiVo. Also, none of the plugs from the entertainment equipment have a third ground prong. We tested each one seperately, (completely disconnected from all the other equipment) and still had these readings. I asked 2 electrician friends and they had no ideas. The problem is I have no idea what to do! It's not noise, it's electricity, and it shocked our cable guy when he touched the coax and hot water heater.
How can these things backfeed 20volts each!??