Quote Originally Posted by e-engineer View Post
Guys,

Try a little test for me. Take a standard television set that does not have a 3 prong, grounded plug. Disconnect your coaxial cable and any other AV connections. Take a voltmeter. Measure the voltage from any metal (coax connector shield/hot, RCA shield/hot) and you will find 60+ volts on it. This is the way ungrounded TV's are designed. Any plasma/LCD TV will have a grounded plug, you will not see the same voltage on a grounded TV.

So, if the CATV system is not bonded/grounded in accordance with NFPA 70 250.94, then the CATV system itself will see this voltage on the lines feeding back.

Simple little experiment, it's nothing more than the voltage from the TV power supply capacitors bleeding off. Not enough to really shock you, but enough to startle you for sure.

J
Not a chance I would agree with that.
There should be absolutley nothing , nada , zero volts let alone 60 volts out putting from the TV's F connector at the tuner block or any other point.

There is no way UL would allow this to be a safe normal condition.
50 or 60 volts is a fair charge and if there is 5 ma or more this potentionally can kill.

The caps from the power supply don't normally feed back through the circuitry on a 2 conductor power cord.
If you had 50 or 60 volts feeding back through the tuner block I doubt the TV would be working or not very well at least.

Back in the day when electronic equipment used tubes instead of solid state components .... then maybe you might find feed back voltages . The metal chassis were notorious for being hot for grid voltages..... this is not the way it is with solid state componets used for over 35 years.



If there is voltage on the CATV cable coming into the home then it's the cable company's issue ...... either problems with the distribution amps or from their plant.
If the cable shows clean coming to the house but shows a voltage on the cable in the home then there is a ground issue .... perhaps the cable company ground block or grounding issues within the home.

If there is a cable box involved and the cable coming into the box is clean but has voltage coming out .... it's the cable box.

If there is only voltage coming out of the TV .... the TV is faulty.