View Full Version : Voltage On the "Antenna In" Of TV


ib4it
08-21-09, 11:58 AM
I have a Samsung LN52650R LCD tv. I noticed I was getting a little shock while hooking up my rooftop antenna. I traced it all the way back to the tv. It stays "hot" until I pull the power plug on the tv. It has voltage with no RG6 cable attached.

Is this normal? I wan't to hook up an aplifier next but am a little concerned, paranoid about this.

eyager
08-21-09, 01:53 PM
I would be concerned. It could be the TV has bad component in it that is causing it to leak excess current through antenna connector. You could also have a miswired outlet or perhaps even a grounding/neutral bonding electrical problem with your entire house.

Make sure your antenna and coax are properly grounded. Many people think this step is unneeded, but as you've found out on the roof there is a reason why this is required by law.

EDIT:
Some voltage and current leakage is normal, but only if it falls within acceptable limits. See http://www.repairfaq.org/samnew/tvfaq/tvssconcab.htm

DAP
08-21-09, 03:47 PM
Get an outlet tester (3 pronged plug with 3 neon bulbs) to test the outlet to make sure the three pins of the outlet are connected correctly. You might have another device somewhere in your house that is dumping current into the ground pin. about the only way to test for that is to unplug everything else in the house to see if the voltage goes away.

ProjectSHO89
08-21-09, 04:53 PM
It "should" be impossible for anything related to a receptacle's wiring to cause a voltage to appear on the COAX terminals for a TV set.

That said:

1) Get a meter and measure it to see what you have
2) Call the manufacturer
3) Return it for an exchange or refund.

Servicetech571
08-21-09, 05:55 PM
Take a meter and measure the resistance between the coax connector and the ground on the power plug. Should be less than 1 ohm.

Tschmidt
08-21-09, 06:38 PM
Take a meter and measure the resistance between the coax connector and the ground on the power plug. Should be less than 1 ohm.
I agree if TV uses a grounded plug. I don't know what kind of TVs you guys have but all of ours only have a two-wire plug.

jjeff
08-21-09, 11:21 PM
Maybe commercial TV's? My newer Sony LCD uses a PC type removable plug, but the plug end only has 2 prongs. Some PC monitors may also be grounded.

eyager
08-22-09, 08:28 AM
Here is excellent reference about this topic. http://www.marcspages.co.uk/pq/3333.htm

nybbler
08-22-09, 12:37 PM
If it's a polarized plug, check the wiring on the outlet. Otherwise it could be a problem with the TV; there shouldn't be enough leakage current to shock you.

ib4it
08-22-09, 01:33 PM
Mystery Solved. VERY temporary fix is in place.

This TV has a three prong plug, plugged into a HT UPS. I checked the Ohm reading between the Hot-ground and neutral-ground and it read a big ZERO. To me this means that I have no ground:):rolleyes:. I ran a good quality extension cord across the room and checked the antenna wire, NO VOLTAGE READING!!!!!

I am happy in the sense that I got to the bottom of this and it is NOT my TV. I am sad because I need to re wire that outlet. This is an old house that has been mostly remodeled and apparently this outlet is one that was not re-wired. The never ending job of homeownership.

I really do appreciate all the responses. Thank you for taking the time. I was "wishing" that perhaps this TV has a built in amplifier power supply or some other bell and whistle feature that caused this.