In article , you say...
There is, in fact, a very sound reason for switching the TV set off first.
Many sets used the 'off' switch action to force the brightness to maximum, thus discharging the EHT reservoir rapidly before the scan collapsed completely.
Failing to use the set's own switch resulted in the dreaded switch-off spot which would ultimately cause a phosphor burn.
Normally I would not be in favour of going to all the trouble of switching off the socket and unplugging the set but I recall one occasion when it might have saved a set from destruction.
Following a thunderstorm in which the aerial was struck by lightning, two blackened holes had been drilled through the paxolin panel holding the aerial isolation components (a shorter distance than through the components themselves!), the mains switch contacts had been welded together and the lightning had jumped from the 13A plug to the socket on the wall - over two feet away, according to the customer!
On the same night, about 2 miles away, another set was left plugged into the mains. In this case, no trace of the aerial was ever found(!) the tuner unit in the TV was completely incinerated inside, the mains switch contacts were welded and the fuses in the consumer unit blown!
Fortunately the set was only a couple of years old and a replacement tuner was still available. In the case of the other set, it was too old for a replacement and would have had to be written off if it had sustained the same damage ...
The first set was a Bush TV53 and the second a Bush TV98, if anybody wants to attempt to date this!