Maybe my tv wants to kill me!

TV's have a hot chassis, and the antenna/cable input is supposed to have isolation. Your isolation has been compromised somehow.

Tom

Maybe, maybe not. The OP used a neon bulb tester which can light up from the minimal leakage current along with the static charge build up to start the lamp.

The only way for sure is to actually check the leakage current, or try and light up a 60watt light bulb between the chassis and either ground or the neutral line.

The OP also did not indicate whether the shock was a single instance or a continual burning/tingling sensation.

Hi and thanks, I was getting a shock by plugging in an all metal coax plug from the communal aerial system. It is not static as it is there repeatedly. I measured with a digital meter on ac range and get 44v, but reversing the leads gives zero. It measures as 24v on the dc range. That's between the tv scart earth and mains earth. Regards, David

You need a leakage meter then to determine what kind of current is actually present. Simply connecting a standard current meter is a bad idea as those have little internal resistance and if the tv is supplying high current, then something will be damaged.

It may be within manufacturing specifications as none of your measured voltages were high enough for a full isolation failure. It is not the voltage that is of concern, but the leakage current. You meter was only placing a few megaohms load between the scart ground and mains ground.

On a 120V typical hot chassis power suuply, the voltage measured to ground would be around 85 volts and will have sufficient current to easily light a 40watt incandescent light bulb when connected between the offending hot chassis and ground.

I would bet that there is only a few uA of leakage current present out of the tv scart connector given the voltages measured across a few megaohm .

You did not mention what was measured on the community arial connector to earth/mains ground. Given what you measured on your scart connector, I am betting on a problem on the ariel line coming in, not your tv set.

Communal aerial earth to mains ground (in the UK by the way) measures zero volts with my digital meter.

Check the mains isolator at the aerial(3 high voltage capacitor. or

1capacitor in ceramic insulator} for leakage if the chasis is' hot'.But if the power supply is the type with 'hot &' 'cold',then check the optoisolator,a high voltage capacitor in parallel with high resistance [>1M ]resistor between the secondary and primary of the chopper{"hot "&" cold"} for leakage.Please use AVO meter with Resistance range at 1kohm to read for leakage.GODLUCK.

Thanks for that. I was wondering if the aerial braiding should be earthed. I thought not, and measured it for resistance. It measures around 15-25 ohm to mains ground, depending which way round my meter leads are connected. Just never thought of the aerial system as being a problem. Not with the ultra fussy british health and safety regulations these days.

Thanks Tom, Regards, David

Do you have a 3-wire house wiring? i.e., live, neutral and ground wiring? Does your tv ac plug uses 3 prongs? If you do, is the ground (round) prong still there? If the ground prong was removed, then when you plug the tv to the outlet it's possible the tv's ac plug is connected the other way, i.e., the neutral prong in the plug gets connected to the live house wire. When this happens, the tv ground chassis may be connected to the live wire. Bobby