I think I might be able to help here.
I do allot of electrical experimenting and have experienced similar things happen to my router (resyning) from some of my experiments.
This particular circuit I was working on involved high voltage arcs and every-time an arc was drawn the internet connection would drop and the router would resync.
This might be what is happening with yours, basically circuits inside of consumer electronics are "joined together" using solder. Its a common thing for these solder joints to eventually crack from the heat inside of the TV. Every time the TV is on the air inside of it gets hot and the solder joint expends and contracts when the inside of the TV chasing cools. Over many cycles this can cause the solder joints to become cracked and a poor electrical connection is being made. And sparking/arcing occurs from the poor solder joint.
Now if this only happens when you turn the TV on it might be in an area of the circuit board that is only needed/draws more power at power on. Also does the display brightness randomly change slightly at all? As that will use a small HT inverter to power the back-light (around 600v-1kV if I recall, this is enough voltage to ionise air and give off a ton of electrical noise if faulty).
It could also be the outlet too, to test simply unplug the TV and plug in a lamp to the outlet and see if you can see the lamp flicker at all. If if flickers or dims then you have a bad outlet which is easily replaced. Just don't do this when you have an inductive load running such as a washing machine/dryer/vacuum cleaner as these can cause lights to dim slightly momentarily when they begin to spin, thus it would be an unreliable test. Or simply plugging the TV into a different outlet in the house would be fine for determining if the outlet is at fault.
We had a similar thing with the outlet that our kettle plugs into and after boiling water you could take the plug out of the socket and the neutral prong would be quite hot!
Not saying the TV is faulty, it could well be something else but its my thought's anyway!
Also what MHC is referring to might sound strange but having an earthed metal cage is called a "Faraday cage". Its the same thing as being inside of a car and having it struck by lightening, the electricity would travel through the cars metal body and then arc from the wheel axils and go directly to ground/earth. It is becuase that would be the least resistive path for the electricity to travel. Same applies to RF interference and more so becuase of the "skin effect" with high frequency's.
Sorry if this makes no sense!
Edited by deleted (Thu 26-Jan-12 19:32:12)