Interesting comment from NEDL saying the problem had been out of their control and the families would have to claim on their insurance. What happened to the legislation that required that the power supply company used to by law maintain the power with limits of +- 5% of the nominal voltage.
It is so simple turn it off. I do, I also have a surge protector. For me it is nothing new, I have heard of televisions catching fire when on stand by for years, so I do not trust anything, plus of course it saves energy. Perhaps we will here from someone who doesn't have time?
If these are actually Digiboxes (Sky) as described and not Freeview boxes then they have to remain connected all the time, otherwise they have to go through a complete boot sequence very time you put the power back on.
Off standy also ,this can give rise to many problems
Many devices when totally disconnected lose all settings and have to go through a re tune sequence each time. Some cheaper items do not have a power switch and so are live all the time. So it will pay to consoder what you have and how it is connected to the main supply.