Hi there. Sort of a long story here...I recently purchased a new projector and surround system because when I pushed the plug from my power strip into the outlet, (it was hanging out partly) there was a spark, and none of my devices worked anymore. We decided not to buy anything new until we grounded the outlet. Once that was grounded I purchased a new surround and a new projector. I hooked my computer, dvd player, and stereo in the the projector and it worked great. Then I connected the projector to my tivo, sparks shot out and shorted out my tivo and brand new projector. I returned the projector and got another. This time I hooked everything up, worked great, then tried a new cable box since my tivo blew up. When I hooked that into my projector, the screen went black. I then unplugged the cable box from the wall outlet, plugged in a new cord (the one that goes from the cable box to the video in on the projector) and then tried to connect the cable box to the projector, sparks flew again and my projector would not work. Since the cable box was not plugged into the wall, I assumed it was a cable problem. I had an electrician come out since cable repair won't be here until Friday. He tested the outlet to make sure it was grounded, it was, checked the cable line with a meter and said it was normal, made sure the house and cable were grounded and they are. I am stumped as to what could be causing this and have a feeling when the cable repair come out they won't find problems either, since my electrician didn't find any. Does anyone have any ideas? Thanks!
There is a good chance your cable line is actually not grounded. The three-pronged (grounded) plugs of most new display products provide a path to earth for ungrounded cable lines. The path usually runs through the motherboard, which stinks, and because your old tv probably wasn't using a grounded plug you were not aware of the issue, which really stinks.
If you run a meter on VAC between the center conductor of the cable and the ground screw on the wall outlet, you'll probably come up with 40-60 volts. If you're feeling brave, you should check the spot outside where the cable meets the dwelling - you'll probably find a bad ground wire. Cable tv should not carry ANY voltage into the dwelling.