Need advice - DC current on exposed metal of LCD television

Hi - I'm somewhat of an electric newbie, and hope you can advise me. Thanks!

I have a JVC lcd TV. Any cable plugged into it is sparking visibly and constantly when touched to any earthed metal surface (eg, my PC, via VGA cable). The sparks do not cause any visble damage, but can be felt (by accident!). I tested as follows with a multimeter, between the TV set and an earth terminal.

17v (16.5-17.1) DC from any exposed metal portion of the frame (eg, RCA ports).
DC current of 0.01, multimeter set on 20ma
0v AC

TV is plugged into an unearthed powered indoor aerial, and is not earthed itself. The current appears to have caused some component damage to my PC. My questions are as follows:

-is this normal? The sparking seems a little extreme.
-if not, is it possible to get this rectified?
-how likely is it to cause damage to other devices, grounded and ungrounded?
-finally, are there any good resources you recommend for understanding amperage measurements? (I'm googling away, but any recommandations would be welcome)

Your PC or TV or both do not have a ground connection. A ground connection for PC is important, otherwise at time it may result in damaging computer. If you can provide good ground connection to both TV and Computer the problem should be solved.
Raoof

Re: Need advice - DC current on exposed metal of LCD televis

Thanks for the advice. My PC is grounded (my psu has a ground lead hooked directly to the case, which I've tested.)

Given that my television is not built with a ground, and there is no external aerial/earthed aerial available, is it safe to simply run a (insulated!) wire from the metal frame to an earth? (i assume so, but assumptions can be costly, sometimes.)
Cheers!

Re: Need advice - DC current on exposed metal of LCD televis

Try unplugging the powered aerial to eliminate that. Though you say it is unearthed, it could, by poor design, be presenting a voltage to what should really by a floating ground of the TV.

If you can feel the voltage, it could be dangerous (both to you and your peripheral equipment). You wouldn't normally "feel" anything below about 50V so your tested voltages may be misleading if the source is high impedance (it could, for instance be around mains voltage until you connect anything to it - testing with an oscilloscope would be interesting though not practical unless you have access to one).

I would be fairly confident that the TV is well designed to ensure isolation of its floating ground from any voltage to true ground/earth.

One last thought, is there any chance that the wiring of your mains socket is incorrect (i.e. live and neutral transposed)? That can give unpredictable symptoms.

3phase