On 09/01/11 09:07, nev young wrote:
I suspect it is caused by a (static?) discharge as I have been able to measure a potential of about 150 volts between the two devices (laptop & TV set) although there is no current available to do any (much) damage.
I just fall back on the old hardware adage of "don't plug or unplug under power".
That isn't static, it sounds like a ground level mismatch between the two devices.
If your TV set has an earth pin connection then I would get the set PAT tested or have the earth bonding in whatever mains socket you have it plugged into checked out.
Laptops are a bit of a funny beast when it comes to Ground as they tend not to have a ground connection bonded to mains earth through the PSU so there is potential (lol) for a ground mismatch when compared against another item. But a 150v PD between the two would suggest to me that one of them is faulty or there is something very wrong with your mains wiring.